Slashdot Mirror


Hynix 48-GB Flash MCP

Hal_Porter writes to let us know that the third-largest NAND chip maker, Hynix, has announced they have stacked 24 flash chips in a 1.4mm thick multi-chip package. It's not entirely clear from the article whether the resulting 48-GB device is a proof of concept or a product. The article extrapolates to 384 GB of storage in a single package, sometime. Hal_Porter adds: "It's not clear if it's possible to write to them in parallel — if so the device should be pretty damn fast. The usual objection to NAND flash as a hard drive replacement is lifetime. NAND sectors can only be written 100,000 times or so before they wear out, but wear leveling can be done to spread writes evenly over at least each chip. I worked out that the lifetime should be much longer than a typical magnetic hard disk. There's no information on costs yet frankly and it sounds like an expensive proof of concept, but it shows you the sort of device that will take over from small hard disks in the next few years."

129 comments

  1. I, for one ... by Anonymous Coward · · Score: 0, Funny

    ... welcome our new 48GB overlords.

    1. Re:I, for one ... by Anonymous Coward · · Score: 0

      my 1TB overlord can kick your 48GB overlords ass!

  2. Database servers by gnuman99 · · Score: 4, Interesting

    Random seek is probably one of the biggest bottlenecks in large databases. There are even databases that optimize reads/writes to be more consecutive on the disk. A drive like that would throw that problem out of the window.

    1. Re:Database servers by pilgrim23 · · Score: 0, Offtopic

      "...that the lifetime should be much longer than a typical magnetic hard disk." ... I am curious about how that lifetime is determined. As a retro-computist hardwre buff I tinker with old hardware all the time. One example (of many): I have a Apple /// with 5mb (yeah 5mb) ProFILE drive. I think this beast was made in 1981 and it still runs just fine. I have a few slightly older hard drives too. I am not sure how an average lifetime is determined but I actually play with hardware that is over a quarter century old. If a NAND can last that long I will be impressed...

      --
      - Minutus cantorum, minutus balorum, minutus carborata descendum pantorum.
    2. Re:Database servers by CastrTroy · · Score: 4, Insightful

      You'd have to look at how much actual reading or writing to the drive is done by a computer from that era. Currently, hard drive space is really cheap, so we write lots of stuff to the disk, like temp files, log files, swap out programs, and even with some filesystems and operating systems write to the drive every time a file is accessed. A computer from that era wouldn't be writing so much stuff too the hard drive, as hard drives were small and expensive. It would likely only write to the drive when you need a program to save actual human created data, or when you install a new program. Reading would only be done when you start up the computer, a new program, or load a file.

      --

      Anthropic principle: We see the universe the way it is because if it were different we would not be here to see it.
    3. Re:Database servers by Surt · · Score: 2, Interesting

      http://download.micron.com/pdf/datasheets/flash/na nd/4gb_nand_m40a.pdf
      promises data retention of 10 years. I would guess that it will function longer than that, but only if you refresh the data.

      --
      "Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
    4. Re:Database servers by Klinky · · Score: 1

      But you then have the problem with many databases being much larger than the 48GB listed or even the 384GB. Even if you could buy it today it's probably not very cost effective. Adding more ram or working on better caching solutions may prove to be more valuable. Also it's good to note that while flash meory does have faster seeks they are around 500ns - 1ms. That's quicker than a HDD sure, but it's still exponentially slower than DRAM. see However, this will probably be the wave of the future once we start seeing prices come down and the limits of magnetic storage reached. But with SSDs you'll always have magnetic storage which is going to be exponentially cheaper probably for the next decade or so. Just when the price/performance advantage becomes worthwhile will we really see these take over.

    5. Re:Database servers by Xichekolas · · Score: 1
      --

      Self-referential Sigs are cool on /. these days...

      54

    6. Re:Database servers by Anonymous Coward · · Score: 0

      you MUST be new here

    7. Re:Database servers by Atzanteol · · Score: 1

      But you then have the problem with many databases being much larger than the 48GB listed or even the 384GB.

      Let me introduce you to our friend RAID.

      --
      "Ignorance more frequently begets confidence than does knowledge"

      - Charles Darwin
    8. Re:Database servers by Anonymous Coward · · Score: 0

      I'm AC#59. What's your anonymous coward id?

    9. Re:Database servers by Jeppe+Salvesen · · Score: 1

      Well, I'm rooting for this solution for an index tablespace (or .MYI on a MyISAM database), and a regular raid for the actual data. I think that combo would fly, as the tree operations on the index thrives on low latency - and the consecutive reads/writes of table data thrives on regular disk devices as they tend to have a good throughput.

      --

      Stop the brainwash

    10. Re:Database servers by Anonymous Coward · · Score: 0

      Why the hell would we PC users pose as faggots? You must think your shit don't stink to consider yourselv... hey, wait a minute! You're that fucking queer from the library story, aren't you? The one that gobbled a huge chunk of shit? Must have been a cinch after swallowing what Jobs has been feeding you for years, eh? *wink, wink, nudge, nudge*

    11. Re:Database servers by Anonymous Coward · · Score: 0

      "I am not a numbah! I am a FREE anonymous cowahd!"

      (http://www.the-prisoner-6.freeserve.co.uk/music/n ew_prisoner.mid)

    12. Re:Database servers by Klinky · · Score: 1

      Well yes, but then you have the problem of how much these things cost. They are still a bit out of the range of cost effectiveness.

    13. Re:Database servers by Atzanteol · · Score: 1

      Ah, right. I think I misunderstood your point a bit, or jumped to an incorrect conclusion...

      --
      "Ignorance more frequently begets confidence than does knowledge"

      - Charles Darwin
  3. 48 GB = 384Gb by sirket · · Score: 5, Informative

    The article does not extrapolate to 384 GB of storage- they extrapolate to 384 Gb of storage which is 48 GB of storage. bits != bytes.

    1. Re:48 GB = 384Gb by sirket · · Score: 2, Informative

      JHust to clarify- the company mentions possibly going to 28 stacked chips which would be 448 gigabits (not gigabytes) of storage- or about 56 GB of space. Now as flash chips grow in size- this could double (assuming 32 Gb NAND chips which are becoming available) to 96 or 112 GB of storage or more (assuming larger chips).

    2. Re:48 GB = 384Gb by thatskinnyguy · · Score: 1

      384,000,000,000bits / 8bits in a byte = 48GB / 24 flash devices = 2GB per device. Seems like they could almost do better. I'll give it some time. (Impatient for SSHD)

      --
      The game.
    3. Re:48 GB = 384Gb by HiThere · · Score: 1

      But what they *ought* to do is figure out how to stack 33 or 35 planes (1 word + parity). I suppose that they could do fancier error correction...but this is a ram chip, not a computer.

      Anyway, then if they could read/write all planes in parallel you'd not only have fast access, but also simple addressing. (I.e., you could reasonably do I/O to a single column...admittedly slower than block transfer, but nicer if you only need to change one word.) This would be more important if memory usage cycles were more important, and if there were block parity, that would still need updating, but potentially a very nice approach.

      --

      I think we've pushed this "anyone can grow up to be president" thing too far.
    4. Re:48 GB = 384Gb by timeOday · · Score: 3, Insightful

      But these appear to be be tiny (for mobile applications).... you could fit an enormous number of them into a 3.5" (or even 2.5") hard drive enclosure, if you can afford it. Put in a controller that can read and write to, say, 16 chips in parallel, and you would have a monster hard drive in every respect.

    5. Re:48 GB = 384Gb by steelfood · · Score: 1

      I don't know which K you're using, but in my world, there are 1000 bits per Kb, 8 bits per byte, and 1024 bytes per KB.

      Which means 384 billion bits is 48 billion bytes, which is only 44.7GB.

      HDD manufacturers want 1000 bytes per KB, but I don't buy that at all. It no different from the ram manufacturers rounding up 536866816 to 512MB when 512MB is actually 536870912.

      --
      "If a nation expects to be ignorant and free in a state of civilization, it expects what never was and never will be."
    6. Re:48 GB = 384Gb by Anonymous Coward · · Score: 0
      Your world is small... these days, it really depends on where the bytes are used.
      If you need to be 100% clear on this, the safest thing is to use the IEC standard prefix.

      1024 byte = 1 KiB
      1048576 byte = 1024 KiB = 1 MiB
      And so on. MiB is in full "mebibyte". So you also get: "kibibyte" and "gibibyte". (Yes, I know! I didn't invent these names.)

      A gem from the wikipedia article text (didn't know this myself):

      CD capacities are always given in binary units. A "700 MB" (or "80 minute") CD has a nominal capacity of about 700 MiB (approx 730MB).[47] But DVD capacities are given in decimal units. A "4.7 GB" DVD has a nominal capacity of about 4.38 GiB.[48]

    7. Re:48 GB = 384Gb by GenP · · Score: 2, Funny

      I for one welcome our able-to-max-out-SATA NAND flash overlords.

  4. 48GB? by Tiroth · · Score: 1

    Looks like people are confusing bits and bytes. 48GB does not appear in the article anywhere, so I assume this is obtained by dividing 384Gb by 8.

    24 layers x 16Gb package = 384Gb, so the article itself is consistent.

  5. Why only 100,000 times by BlowHole666 · · Score: 1

    Why is it that you can only write to a NAND gate 100,000 times before it stops working? Is it the material they are using or something with the voltage?

    --
    I smoked pot once. But I DID NOT inhale. Will you hire me?
    1. Re:Why only 100,000 times by Anonymous Coward · · Score: 3, Funny

      The NAND gate is a union worker, also entitled to a smoke break every 3,000 write cycles.

    2. Re:Why only 100,000 times by jandrese · · Score: 5, Informative

      It's due to the way Flash works. A flash bit is basically a conductor surrounded by an insulator. To store a bit, you apply a large charge to the insulator to increase the charge of the conductor, basically your burning through the insulator to get your charge though. Once it is on there, to read the charge you have to apply another large charge to the insulator and see if the resultant charge is n or n + m. The m factor comes from latent charge on the conductor.

      Anyway, the upshot of this is that because you have to constantly burn charge through the insulator to use the part, eventually you basically burn out the insulator and cause it to leak charge. Once it starts leaking, you lose your stored bits and the part is useless.

      --

      I read the internet for the articles.
    3. Re:Why only 100,000 times by BlowHole666 · · Score: 1

      Thanks. Yeah I remember from my circuits class designing memory but now that I think about it we had a constant power supply to keep the charge. In this case you don't so you have to keep it some other way. Thanks for the reply.

      --
      I smoked pot once. But I DID NOT inhale. Will you hire me?
    4. Re:Why only 100,000 times by Knara · · Score: 1

      Keep in mind that the 100,000 writes number is a stock number that seems to go up all the time, not that this comment directly addresses the "why".

    5. Re:Why only 100,000 times by Bacon+Bits · · Score: 2, Interesting

      It's wholly one of mechanical endurance of the components, AFAIK. The gate is wedged, for lack of a better term. Everything physical wears out. It was much worse in the early 1990s, but whole orders of magnitude in improved performance have been made since then.

      I've never seen a study conclude that the write limitation on NAND flash-based devices is a significant impact. Some of the studies have cited worst case scenarios of 50 years of continuous operation. It is far more likely that the device will physically fail due to other means rather than fail due to NAND erasing wear. In any case, I've never seen anyone claim that a solid state disk is going to fail before a mechanical magnetic disk simply due to NAND erasing wear. Indeed, the articles that actually go into it make pretty strong claims that the endurance of flash media is far above that of current mechanical-electromagnetic designs. Three or four times the lifespan.

      --
      The road to tyranny has always been paved with claims of necessity.
    6. Re:Why only 100,000 times by EnderWiggnz · · Score: 0

      the funny thing is, i haven't seen a manufacturer list MTBF in write cycles in over 5 years. wt the newer materials, and ar levelling, the worst that i've seen is a mtbf of 1 million hours of continuous use. there is no ention of write cycles , ever!

      --
      ... hi bingo ...
    7. Re:Why only 100,000 times by treeves · · Score: 1

      So is the summary (I didn't RTFA of course) misleading by continually referring to NAND flash having this limitation? Doesn't it also apply to NOR flash?
      OK, I just looked at the Flash entry on wikipedia, and it appears that it's even worse for NOR flash.

      --
      ...the future crusty old bastards are already drinking the Kool-Aid.
    8. Re:Why only 100,000 times by petermgreen · · Score: 1

      Yeah memory that needs power to keep it's contents is known of as a ram. Much faster than flash and basically no limit on write frequenc but the boards to make it act like a disk are expensive and you have to make damn sure it keeps power if you have anything important stored there.

      --
      note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register
    9. Re:Why only 100,000 times by networkBoy · · Score: 4, Informative
      Flash is rated in erase cycles, not write cycles. Erase is the most damaging event to the tunnel oxide layer in the device, which is why they fail.
      Flash Cell stackup (same for NOR and NAND, the interconnection of cells determines what type of array it is):

      G - gate (metal)
      ONO - Oxide/Nitride/Oxide layer
      FG - Floating Gate (Poly)
      tOx - Tunnel Oxide (very thin)
      Si - wafer (NPN/PNP wells) -nB
      --
      whois gawk date unzip strip find touch finger mount join nice man top fsck grep eject more yes exit umount sleep dump
    10. Re:Why only 100,000 times by Intron · · Score: 1

      For a laptop drive replacement, drop cycles are just as important as erase/write cycles. After a few drops a laptop harddrive starts going "eeeeeeeeek eeeeeeeeeeek eeeeeeeeek" whereas I hear no sound coming from the flash drive.

      --
      Intron: the portion of DNA which expresses nothing useful.
    11. Re:Why only 100,000 times by cheater512 · · Score: 1

      I thought that only writes were impaired, reads didn't affect the flash at all.

      Your explanation would mean that both reads and writes degrade the flash.

    12. Re:Why only 100,000 times by jandrese · · Score: 1
      --

      I read the internet for the articles.
    13. Re:Why only 100,000 times by Anonymous Coward · · Score: 0

      Another case where the original word doesn't mean what you think it means and the opposite word doesn't even exist in the dictionary (downshot).

    14. Re:Why only 100,000 times by JoelKatz · · Score: 1

      For practical purposes, there's no difference. Every write (to a particular cell) is preceded by an erase (that includes that cell).

  6. FAT32 by garlicbready · · Score: 1

    Just think 48 GB of storage space on a Fat32 Filesystem
    what a waste ...

    1. Re:FAT32 by TeknoHog · · Score: 1

      Imagine a Beowulf cluster of 48 HP 48GXs with 48 GB each.

      --
      Escher was the first MC and Giger invented the HR department.
    2. Re:FAT32 by Anonymous Coward · · Score: 0
      Just think 48 GB of storage space on a Fat32 Filesystem
      what a waste ...


      Imagine your post. What a waste. Flash != Fat32

    3. Re:FAT32 by operagost · · Score: 1

      Fortunately, Microsoft hard-coded XP and later to not format partitions larger than 32 GB with FAT32. It's always possible these will ship with FAT32 via the use of some other utility, but it seems unlikely.

      --

      Gamingmuseum.com: Give your 3D accelerator a rest.
    4. Re:FAT32 by Hal_Porter · · Score: 1

      You can use this

      http://www.ridgecrop.demon.co.uk/fat32format.htm

      FAT is old fashioned to be sure, but it you can do both read and write on pretty much any OS without installing a driver. And any OS that supports USB keys bigger than 2GB supports FAT32 and thus supports volumes upto 2TB.

      --
      echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;
  7. swap space / tmpfs / cacheing by lobiusmoop · · Score: 2, Interesting

    Given the low price of RAM these days (1 or 2 gigs being standard) minimising the need for swapping, and availability of tmpfs in the Linux kernel, I'm surprised there are not more flashdrive based linux boxes available these days.

    --
    "I bless every day that I continue to live, for every day is pure profit."
    1. Re:swap space / tmpfs / cacheing by Jeff+DeMaagd · · Score: 2, Insightful

      Have you actually bought a sizeable flash drive? 4GB CD cards are starting to be common, I think CF cards are the most affordable flash drive that you can reasonably use as a system drive. But for the same price, you might buy a 300GB hard drive. Not only that, there doesn't seem to be any affordable SATA-based flash drives, which is quickly becoming the only drive connection type found in computers.

      So it would work great for a network terminal, there doesn't seem to be enough for most people to use just yet.

    2. Re:swap space / tmpfs / cacheing by Com2Kid · · Score: 2, Interesting

      2GB SD cards are still a better band for your buck, typically. In the very least, compatibility is better. :)

      You can get them pretty easily for $20 a pop.

      Amazingly enough Amazon has 2GB SD cards cheaper than Newegg. $15 a pop (no free shipping though!)

      That is $30 for 4GB, or $60 for 8GB.

      Not quite enough to get Vista up and running, but it should do fine for a stand alone Linux box. :-D

      I wonder what the throughput would be if a proper hardware controller was put in place and you had 50 of those things in parallel.

    3. Re:swap space / tmpfs / cacheing by Anonymous Coward · · Score: 2, Interesting

      I'm surprised there are not more flashdrive based linux boxes available these days.

      There will be several million shortly...

      # Mass storage: 1024 MiB SLC NAND flash, high-speed flash controller;
      # Drives: No rotating media.

      From the OLPC Spec

    4. Re:swap space / tmpfs / cacheing by Spokehedz · · Score: 2, Interesting

      I can't find it now, but I remember a device that would take a bunch of SD cards (like, 4 slots) and would combine them into a big disk that had (I believe) SATA on it. So, you would take a bunch of these cheap 2GB SD cards, and it would make one big disk out of them all.

      http://www.geekstuff4u.com/product_info.php?manufa cturers_id=&products_id=492

      Not it, but close. Also way too expensive.

    5. Re:swap space / tmpfs / cacheing by WuphonsReach · · Score: 1

      The newer SD cards are now being called SDHC (supported by newer devices only). NewEgg had them for $75-$90 when I looked yesterday.

      There are also 16GB ($350?) and 32GB SDHC cards in the pipeline, but still not in the retail channel or priced at a sane level yet.

      --
      Wolde you bothe eate your cake, and have your cake?
  8. Wear leveling? by Jeff+DeMaagd · · Score: 0

    The problem with the concept of wear leveling is that I hadn't been able to find any specs on such a feature, or whether it actually exists in a product. From what I've heard of it, it would seem that it would only wear-level the free space and often-written files, so writes could still easily hammer some areas more than others, and it gets worse the more you fill up a drive. I'm not sure how it would work the way it's claimed to work, the system would work best if it kept track of the number of writes to a given sector, but that seems like quite a bit of overhead.

    1. Re:Wear leveling? by Bacon+Bits · · Score: 1

      You need to have either firmware on the device that handles wear leveling (this seems appropriate for IDE drives or as part of the spec for flash media standards) or use a file system which handles it for you.

      One of the biggest offenders is file systems (such as the default configuration for NTFS) that track last access times. That information is all stored in the MFT for NTFS, so frequently accessed files will be writing to this table constantly.

      --
      The road to tyranny has always been paved with claims of necessity.
    2. Re:Wear leveling? by Anonymous Coward · · Score: 0

      For wear leveling to work efficiently, the medium must have either a rather large set of spare sectors that can be cycled in and out of use, or have some Idea what part of it is unused, i.e. not filled with usable data according to the filesystem that has been used to format it. I can imagine FAT or FAT32 support implemented on such a controller, even with some kind of recognition for partitions, but even then, what happens when the disk is full, and I just repeatedly write over the same set of sectors, chosen to be larger than the suspected number of spare sectors?

    3. Re:Wear leveling? by Anonymous Coward · · Score: 0

      I'm not sure how it would work the way it's claimed to work, the system would work best if it kept track of the number of writes to a given sector, but that seems like quite a bit of overhead.

      All the wear levelling algorithms I've heard of being actually implemented fell into one of two categories:

      1. pseudo-random sector ordering - the position of a sector on the physical media is rotated every time it's written according to a pseudo-random algorithm that should ensure near-equivalent writes to all areas of the media.

      2. The flash chip tracks writes by sector or block, and always chooses the least-written free sector to store a new file. This can be done in a data-agnostic method inside the addressing circuitry, and therefore should be fs-agnostic.

      Both of these, of course, use a lookup table to dereference - one's doing it in flash, the other in the OS' filesystem driver. I think Windows' mass storage drivers try to use #1 where possible, but don't quote me on that!

    4. Re:Wear leveling? by Anonymous Coward · · Score: 0

      Flash technology does not implement wear leveling at all, it is completely done by the controller that talks to the flash (be it NOR, NAND, etc). There is some hybrid flash technology (oneNAND, trustedFlash, etc) that include a controller in the flash package to reduce integration costs, but there is still a controller in front of the flash technology.

      From my knowledge (working in the industry), it is exceptionally rare for the controller to understand the filesystem that is on the flash. The controller works in terms of reading/writing LBAs, and not what data is stored. Most of the engineers that I deal with (from multiple companies) do not know the differences in the filesystems, and wouldn't be able to tell you what sector the PBA, FAT are in, let alone the write characteristics for them.

      Wear leveling comes in a variety of forms, and has differences in the performance of the device, and the life of the device. The two main buckets for wear leveling are static and dynamic (and I always confuse the two, so forgive me).

      For the difference I'm going to use LBA and PBA. LBA = the logical block address that the host/filesystem believes it is writing. PBA is the address that the flash controller is actually writing (it's a little more complicated, but this works)

      In all cases there is a pool of PBAs that are reserved by the flash controller for wear leveling. These cannot be directly addresses by the host/filesystem, effectively they are outside the range of known LBAs.

      My defintion today of static:
      Only data being written is wear leveled. Data that is written once, but never again does not get wear leveled. For example, write data to LBA 0, 1 and 2. The flash controller writes these to PBA 0,1, and 2. The host writes new data to LBA 2. The flash controller writes this data to PBA 3 and moves PBA 2 back into the free area.

      My definition of dynamic:
      All data is wear leveled, regardless of write or read. This can be done similar to a JAVA garbage collection routine, or other algorithms. For example (an extremely poor example), write data to LBA 0, 1, and 2. The flash controller writes these to PBA 0, 1, and 2. The host writes new data to LBA 2. The flash controller does PBA 0 -> PBA 1, PBA 1 -> PBA 2, new data -> PBA 0.

      You should also check your 100,000 write cycles. MLC NAND flash is typically quoting between 5,000 and 10,000 write cycles. SLC NAND flash varies between 10,000 and 100,000 write cycles. The degradation in the flash life time is causing most vendors to move to my definition of dynamic wear leveling to keep the life of the device on par with what you have experienced to date.

    5. Re:Wear leveling? by networkBoy · · Score: 1

      Flash devices have a small microcontroller already embedded in them to control programming and erase voltages. It also is responsible for wear leveling (at least in NOR devices).

      --
      whois gawk date unzip strip find touch finger mount join nice man top fsck grep eject more yes exit umount sleep dump
    6. Re:Wear leveling? by dan42 · · Score: 1

      My company uses a flash filesystem from Intel for flash in our products.
      It features "wear-leveling", but a big problem is that in our system ~50% of the storage space has static files that are never modified, so that area is never erased. The wear-leveling only works well if ALL the files are modified frequently. If we fill the flash up with files and then modify only one file 100,000 times (can be done in about an hour or so), the product is dead.

  9. I noticed... by thatskinnyguy · · Score: 1

    The sizes of SSHDs reported recently are kinda like the odd sizes of SCSI drives.

    --
    The game.
  10. Flash lifespan in persective by G4from128k · · Score: 4, Interesting

    Even at only 1,000 writes of reliable lifespan, 48 GB could handle 48 TB of writes or over 4,000 hours of continuous writing of compressed HD video (or about 2 years of 40 hr/week writes of a video stream). Checking my average usage of disk I/O finds that I only average about 2 GB of writes per day which would suggest that this device would last me 24,000 days (or 65 years). And if the life is 10,000 or 100,000, then I'd see 10X or 100X that lifespan.

    Your mileage may vary, but I'd bet that 99% of users would never keep their computer (especially a laptop that is the more likely application for flash-based drives) for long enough to see the disk fail from wear.

    --
    Two wrongs don't make a right, but three lefts do.
    1. Re:Flash lifespan in persective by drrck · · Score: 1

      I don't think that is would "just fail" either. What you should see is a slightly lesser overall capacity when those sectors become marked as unavailable, right?

    2. Re:Flash lifespan in persective by russotto · · Score: 1

      Unfortunately, wear leveling also means that when one cell fails, many others are likely to go real soon now. So when you start getting bad sectors, time to replace the device.

    3. Re:Flash lifespan in persective by compro01 · · Score: 1

      though keep in mind that the 48GB might really be 49 or 50* to provide spare sectors in the same manner hard drives do.

      *numbers not necessarily based on any factual information.

      --
      upon the advice of my lawyer, i have no sig at this time
    4. Re:Flash lifespan in persective by smallfries · · Score: 2, Informative

      You're assuming that the 2GB a day could be spread evenly over the disk. This would vary depending on how much free space you have on the device. If your drive is 1% full then you can distribute your writes over the other 99%. But most people don't keep their storage mainly empty. In fact people tend to run just under the limit - hence the saying that crap always expands to fill the available space. If your drive was 99% full then you can't distribute the writes over the parts with data (as it would have to be moved somewhere else negating the benefit), and then you run into the problem with the limited duty cycle.

      Having said all of that, I don't think my throughput is anything like 2Gb, and most of it would be swap (hasn't happened much this past couple of years) and /tmp. Given that /tmp would be better suited to a RAM disk anyway I don't think that either would pose a problem, and the lifespan of these flash disks is probably comparable to a magnetic platter. As another reply pointed out, when the duty cycle is exceeded you can't alter the sector anymore. On a magnetic disk when a sector dies you're SOFL. Once the price comes down to an afforable level these drives will be beautiful...

      --
      Slashdot: where don knuth is an idiot because he cant grasp the awesome power of php
    5. Re:Flash lifespan in persective by Anonymous Coward · · Score: 0

      Flash drives moves the data to distribute writes so it does not matter how much space one actually uses. This data movement is completely hidden from OS and for all purposes all those flash drives/cards look like normal disk.

      Note also that when the data movement algorithm is not done right, the data on the flash can be corrupted when it is powered off during writes. And since the moves are hidden, using a journaling file system does not help to protect against such corruption.

    6. Re:Flash lifespan in persective by msgtomatt · · Score: 2, Interesting

      Your calculation of 24,000 days is when the drive reaches total failure. Your logic does apply to camcorder applications in which data is always written sequentially. But, in PC applications you do not write the information as a bit stream, you write things fairly randomly. When you change the contents of a file without changing the file size, you update the same physical memory locations. So after you update your file a 1,000 times, it becomes corrupted and you loose your data. Once a single byte becomes corrupted the entire sector can longer be used. So in the worse case scenario, this fancy drive would not even last you a day, before you started to loose information.

      To prevent data loss, these drives will require a good CRC algorithm or a RAID configuration that can repair damaged files when they are moved to new sectors. Also, it might be possible to convert the random access to sequential access, by moving the file the end of a circular stream buffer every time it is written too. But this would lead to fragmentation problems, that might be impossible to solve.

    7. Re:Flash lifespan in persective by ivan256 · · Score: 1

      You're assuming that the entire capacity of the chip would be exposed to the end user, and none would be reserved for dynamic load leveling.

      You're also assuming that unchanged data would never be moved by the load leveling algorithm.

      I don't think either are valid assumptions, and you're just plain wrong.

    8. Re:Flash lifespan in persective by smallfries · · Score: 1

      OK, all three replies came up with the same points but I'll reply to you since you've put them most succinctly. Your point about reservation makes sense, and it does change the overall picture. Spare blocks on the disk would increase the ability to do load leveling. So lets consider the case where we have a disk with 10 blocks, and lets say 4 are free (these can be a mixture of really free, and reserved blocks). If I repeatedly write to a used block (updating / overwriting) then I have five choices of where to put the data - either the original block, or mark that block as free and pick one of the other 4 blocks.

      So I claim that the load can be leveled over 50% of the disk at most - this depends entirely (as you've pointed out) on my second assumption. If I decide that I'm going to pick one of the other 5 used slots to write to, then I have to keep that data. So that block needs to be copied to one of the original choice of 5 places. Unless I choose to keep the dirty data in memory, and hope that I don't run out of storage / lose the power then I can indeed level over all 10 blocks in the disk. But is it reasonable to assume that I can cache the dirty values this way to level over the whole disk rather than just the free space?

      --
      Slashdot: where don knuth is an idiot because he cant grasp the awesome power of php
    9. Re:Flash lifespan in persective by ivan256 · · Score: 1

      So that block needs to be copied to one of the original choice of 5 places. Unless I choose to keep the dirty data in memory, and hope that I don't run out of storage / lose the power then I can indeed level over all 10 blocks in the disk. But is it reasonable to assume that I can cache the dirty values this way to level over the whole disk rather than just the free space?


      When you move a block, you don't have to "cache" the data. You wouldn't erase the data from the original location until it was successfully written to the new location. You also wouldn't report the incoming block as successfully written until the entire process had been completed, thus the only thing you could potentially lose in the case of a power loss would be the in-flight operation.... Which you should have already considered potentially vulnerable to power loss anyway.

      The short answer is "yes". You can reasonably assume that you can level over the entire pool of blocks in this fashion while maintaining the integrity of the previously committed data. Existing load leveling algorithms already do this.
    10. Re:Flash lifespan in persective by smallfries · · Score: 1

      If I write to a block that is already in use (say 2) then I have two blocks in flight, my new block N, and the contents of block 2 which either have to go somewhere else or get cached in memory. So *moving* the contents of a block so that I can write into that location takes two writes instead of one. How is this improving the duty cycle?

      --
      Slashdot: where don knuth is an idiot because he cant grasp the awesome power of php
    11. Re:Flash lifespan in persective by Anonymous Coward · · Score: 0

      Flash doesn't write over the same spot over and over if you're updating the same file. Flash drives use wear leveling - edit and re-save a file and it's actually saved to some other "empty" spot. (File fragmentation isn't a problem, since there aren't any read/write heads to thrash around as in a magnetic drive). You'd only burn through specific parts of a flash drive if you do a lot of writes while the drive is nearly full.

      Further: a quick googling reveals that these drives can handle a million writes per sector.

    12. Re:Flash lifespan in persective by Kjella · · Score: 1

      If your drive was 99% full then you can't distribute the writes over the parts with data (as it would have to be moved somewhere else negating the benefit), and then you run into the problem with the limited duty cycle.

      If you got 10,000 write cycles, after 9000 write cycles to a block spend one extra cycle (that's 0.01%) to swap places with a 100 write cycles block. Don't make this more complicated than it nees to be.

      --
      Live today, because you never know what tomorrow brings
    13. Re:Flash lifespan in persective by ivan256 · · Score: 1

      First off, you only have one block in flight, because you don't erase the old block off the original location until it's successfully written to the new location. It doesn't have to be cached anywhere during this process for integrity purposes.

      Second of all, it improves duty cycle because you are moving static data to a more worn area in order to bring a less used block into service. Data that lives on a block with a low write count (relative to the other cells on the device) is unlikely to be written frequently (history shows it hasn't been). Since there is a low expectation that data will be written, you can move it with a reasonable expectation that while it increases wear very slightly, in the long term it will balance out the wear of the cells. It's called "load leveling" because it distributes the wear, not because it reduces the wear. The idea is that you want all the cells to wear out at about the same time, rather than burning through a few very quickly.

    14. Re:Flash lifespan in persective by Hal_Porter · · Score: 1

      You're assuming that the 2GB a day could be spread evenly over the disk. This would vary depending on how much free space you have on the device. If your drive is 1% full then you can distribute your writes over the other 99%. But most people don't keep their storage mainly empty. In fact people tend to run just under the limit - hence the saying that crap always expands to fill the available space. If your drive was 99% full then you can't distribute the writes over the parts with data (as it would have to be moved somewhere else negating the benefit), and then you run into the problem with the limited duty cycle.

      Wear levelling happens inside the device - the OS can't see it.

      So even if you keep writing to the same logical sector over and over again that physical location moves around so that the erase count remains the same for each erase unit. The device has just needs to keep track of the mapping from logical blocks that the OS uses to physical blocks which are an actual location in flash.

      It has to be like this, since all filesystems tend to write to the area at the start of the disk very frequently. On FAT the FAT needs to updated everytime a file grows. On EXT2/3 or NTFS it's actually worse - the inode needs to be updated on file growth or when the file "last accessed time" changes. People have worked on "last accessed time" problem though - XP only updated it with a one hour granularity, and Vista disables it by default. Linux has a relatime mount option.

      --
      echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;
    15. Re:Flash lifespan in persective by smallfries · · Score: 1
      OK, I see what you're saying now. We're using a slightly different definition of "in-flight".

      Second of all, it improves duty cycle because you are moving static data to a more worn area in order to bring a less used block into service.

      It's called "load leveling" because it distributes the wear, not because it reduces the wear.

      Thanks for the explanation - it makes a lot more sense now. Yes, both my original assumptions were complete tosh then :)
      --
      Slashdot: where don knuth is an idiot because he cant grasp the awesome power of php
  11. The article extrapolates to 384 GB... by crvtec · · Score: 1

    "The article extrapolates to 384 GB..."

    This is one case where I am DEFINITELY not RTFA.

  12. implications of flashing by one_who_uses_unix · · Score: 1, Funny

    It used to be that there were serious implications if you engaged in flashing, potentially including jail time!

    The world has come a long way when any geek can flash thousands of times and not have problems with his hard disk.

    --
    KK4SFV
    1. Re:implications of flashing by everphilski · · Score: 0

      when any geek can flash thousands of times and not have problems with his hard disk.

      in a row?

  13. IPod by dazedNconfuzed · · Score: 3, Funny

    iPod Touch, meet Hynix 48-GB Flash MCP!

    --
    Can we get a "-1 Wrong" moderation option?
    1. Re:IPod by Anonymous Coward · · Score: 0

      That's not funny. That would actually make it useful.

      Imagine being able to carry around 192GB of music, pictures, and videos! Now there's something I wouldn't mind shelling out $600 for, but only if the price doesn't drop $200 3 months later.

  14. media storage by Floritard · · Score: 2, Insightful

    It is just writing that is limited right? Myself, I'd love to have the space to host all my media, most of which just sits archived on dvd-r. I'd only need to write to the disk once. Seems most people, aside from those who do video production, really only need large amounts of space to serve/store media. Be cool to just keep a 200 gig SATA for regular use and just keep buying these suckers and fillin' them up for all that media. Later, when they're cheap that is.

    1. Re:media storage by Anonymous Coward · · Score: 0

      Bits are stored as electrical charges which can leak over time. There is also a limit of how long the data can remain intact. Typical values are on the order of 20 years or so. That is likely a parameter based on statistical values from accelerated test and not tested on a per chip basis. Local defects/impurities can affect it. I am not also sure if alpha particles from packaging would affect that life time either.

    2. Re:media storage by Bigjeff5 · · Score: 1

      It is just writing that is limited right? Actually, it "flashes" on both read and write, so while limiting your writes will extend the life of the disk, constant reading is just the same as constant writing.

      There's a post above that explains it better but basically, flash writes by bursting a charge through an insulator to the storage bit, changing the charge. To read it sends another burst through the insulator and it reads the value based on what the final charge is (initial burst charge + what was in the storage bit).

      It's the insulator that wears down, and once it does the storage bit can't store anything anymore.
      --
      Security is mostly a superstition... Avoiding danger is no safer in the long run than outright exposure. - Helen Keller
    3. Re:media storage by Aetuneo · · Score: 1

      Cheap as in 4.4GB for between 20 and 30 cents? That's the current price for DVD+Rs, as I recall (HD space is about 1GB for 20 - 30 cents). When you can get a 4GB flash card (SD is a nice form factor - easy to store and move around - so I'll say and SD card) for under 40 cents, it might be ready to compete with DVD+Rs for write once applications. Until then, I'll go with the DVDs, thanks.

      --
      Everything is subjective.
    4. Re:media storage by Floritard · · Score: 1

      Actually that is what I'm talking about. Not necessarily as cheap as DVD-+Rs, but something real cheap that doesn't require swapping out discs that you'd write to only once and read from for the rest of it's life. If it's for movies/music then it isn't as though you're going to be reading the same part of the disk constantly (unless you wanted to watch Caddyshack 1000+ times, and actually I may have done that by now). Solid state HDs would probably be better for this task and they're only going to get cheaper. And I'm not trying to be lazy here, it would just be really cool to have a library of personal media that was easily accessible and completely indexed and tagged with rich media meta-data. Something to sync your iPod to or serve your house's many terminals. Until I can buy a digital jukebox at which I can throw spindles of DVD-Rs with random media formats, I can't really have such a system without terabytes of hot storage.

    5. Re:media storage by JoelKatz · · Score: 1

      I use portable storage devices to move data from one place to another. Generally, I need to remove the old stuff to make room for the new stuff. Until these device become large enough to compete with hard drives, which they are nowhere near, they will tend to be used for volatile, mobile data.

      When your laptop can easily have a 64Gb flash-based storage device, a comparable hard drive will hold 1TB. People have never been satisfied with 1/16th the storage they could have, and I don't think that's going to change.

  15. Re:NAND flash writes by TinyManCan · · Score: 3, Informative
    This is straight bollocks. Its ridiculous to think that you could only write to a NAND block 1000 times.

    Commercial products in the high-end flash space are promising 500,000+ writes.

    We are not talking about glorified thumb-drive flash memory here, but decent chips with good wear leveling and high quality construction.

  16. HyperDrive4 by myspys · · Score: 1

    Something that should be mentioned when talking about these things is HyperDrive4

    1. Re:HyperDrive4 by Surt · · Score: 2, Informative

      Ouch that's expensive. And big (in physical dimensions) compared to:
      http://www.computers4sure.com/product.asp?producti d=5623741&affid=10000483

      I guess it may be somewhat faster, but both are approaching the limits of what you can push through a sata interface.

      --
      "Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
    2. Re:HyperDrive4 by Anonymous Coward · · Score: 0

      So I take it you don't use Linux at all cause some people pronounce it Lie-nux, no Hyundai cars cause you don't wanna murder the Huns, no driving Chevrolets cause you don't want a car that runs on Rolaids considering it rolls AIDs into you. No google cause who wants goo on anything? Remember... watch out for dangling participles.

  17. Re:NAND flash writes by Surt · · Score: 1

    http://download.micron.com/pdf/datasheets/flash/na nd/4gb_nand_m40a.pdf
    Says 100,000 program/erase cycles right on the first page (though I do note they only 'guarantee' 1k writes for the first block).

    --
    "Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
  18. Nice Butt... by eno2001 · · Score: 2, Funny

    ...would you really want to buy something from a company named Hynix? At worst it sounds like a Unix that smells like ass. At best it sounds like a bunch of stoned Unix devels.

    --
    -"...bad old ideas look confusingly fresh when they are packaged as technology" - Jaron Lanier (Digital Maoism on Edge.o
    1. Re:Nice Butt... by Anonymous Coward · · Score: 0

      Nice Butt...
      Thanks! I work out all the time, and reaping burns a lot of calories :)
      -- Death
    2. Re:Nice Butt... by Anonymous Coward · · Score: 0
      Used to be Hyndai until the Hyndai group was forced to sell them.

      BTW, they are now number 2 in ram, mostly database applications.

  19. What about RAID? by GreatBunzinni · · Score: 4, Interesting

    Recently, this whole flash drive business has been popping up in the news, with announcements of a whole gob of commercial solid-state drives based on flash technology and the like. Nonetheless, there is a big void in the flash drive world that, at least at first glance, could be easily filled with trivial technology and off the shelf products but no one seems to be paying any attention.

    I'm talking about RAID + flash cards.

    Flash cards are everywhere and, although their cost per GB is rather high, a 1GB card is easily affordable (1GB microSD card for less than 10 euros) and prices are dropping constantly. If someone decided to build a RAID card reader, we could easily get a foot in the door. For about 60 euros it would be possible to get something between a slowish but reliable 6GB flash drive or a speedy and snappy 1GB flash drive.

    So why exactly didn't anyone thought of this? We already have IDE CF card readers, some models supporting 2 drives, that can be had for about 6 euros. Why not a RAID flash card reader?

    --
    Slashdot, fix your code or at least hire someone who is competent at it to do it for you.
    1. Re:What about RAID? by dangermongous · · Score: 1
    2. Re:What about RAID? by dfn_deux · · Score: 1
      The difference is that not all NAND flash is created equally. The multi-layer cell type which is commonly used in commodity flash devices isn't nearly as fast nor as reliable as the single-layer cell type which is used in the highspeed drive replacements we are seeing hit the market now. The difference isn't trivial when an mtron SLC SSD can do about 5 times the throughput speed of competing higher density SSDs which use MLC nand flash.

      I don't work for mtron, but I am a satisfied customer.

      --
      -*The above statement is printed entirely on recycled electrons*-
    3. Re:What about RAID? by thedohman · · Score: 1

      Oh, you mean a device like a USB Hub + Software RAID?

      Sure, it won't be as fast as SATA or a controller connected to the PCI(express) bus, but it is flash in a RAID and at least as fast as the 5400rpm IDE HD in my laptop.... (no I haven't tried it, but all my flash drives do rate faster than my HD according to SiSoft)

      I remember seeing something like this quite a while ago... I think 256MB sticks were high-end at the time, and they put 4 of them in a single hub to get a full, amazing GB of flash storage. Old News.

    4. Re:What about RAID? by takev · · Score: 2, Informative

      It is called P2

      http://en.wikipedia.org/wiki/P2_(storage_media)

      From the wiki: The P2 Card is essentially a RAID of SD memory cards

    5. Re:What about RAID? by adrianmonk · · Score: 1

      A RAID array of Flash drives? You mean like this? You'll probably want to skip about 2 minutes and 10 seconds into the video to see the interesting part.

  20. 48GB Flash MCP? by tgd · · Score: 1

    I clearly am going to need to be set up for group EIGHT access.

  21. Win2k on Compactflash by Anonymous Coward · · Score: 0

    I've been running Windows 2000 on a 4GB Kingston Ultimate Compactflash card for the past eight months without a problem.

    It has 100,000 write cycles per sector and I reckon about 8000 sectors, so that's 800 million writes for the life time of the card.

    My Win2k writes about 10,000 times per session, so with three sessions a day it should last 73 years. The card only holds its data for 10 years so it's no problem.

    1. Re:Win2k on Compactflash by Hal_Porter · · Score: 1

      What happens if you turn off updating "Last Accessed Time"?

      http://www.pctools.com/guides/registry/detail/50/

      --
      echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;
    2. Re:Win2k on Compactflash by Anonymous Coward · · Score: 0

      I already did that. It reduces the writes.

  22. Not parallel by RecessionCone · · Score: 2, Informative

    It's not clear if it's possible to write to them in parallel -- if so the device should be pretty damn fast. It's pretty obvious that it's not possible to write to this array of chips in parallel, because you just can't fit enough pins in a tiny package to provide the necessary interface for talking to 24 chips simultaneously. Also, take a look at the picture from TFA: http://www.koreatimes.co.kr/upload/news/070905_p10 _hynix.jpg - you can see that all the leads to the different chips are wired to the same pads. This doesn't prove my point - they could all be power or ground connections, but looking at the complexity of the packaging here supports the idea that providing a separate interface to each of these chips would be very expensive and difficult. In short, this is a capacity optimized device, it's not meant to break speed records.
    1. Re:Not parallel by Hal_Porter · · Score: 1

      For cost reasons I think they probably connect the most pins to all the chips - so you can only send data to one chip at a time. My guess is that there is a chip select line per chip though, otherwise it wouldn't work.

      But the interface could be clocked faster than each chip can write. E.g. imagine a device with a write cycle time of 40ns, or 25Mhz. And each cycle is a byte (or larger - x16 devices exist). So the interface can transfer data at just under 25Mbytes per second.

      One chip can't write as fast as that - a 2048 byte page takes 200 to 700us or about 195ns to 340ns per byte. You need to erase to and that takes 2ms per 128K block. So you can clock data into the device betweek 5 and 10 times as fast as it can program it - the sustained write speed is only 2.6-4.5 Mbytes per second.

      But if you had a large block of data (>2K * the number of chips) to write you'd enable the first chip select, clock the 2K data out to the first device and start the program then enable the second chip select and clock the next 2K out to the second one and start that programming too. Only when you have to go back to the first chip do you need to check the status and signal to the OS whether the operation was ok or not. And if you have wear levelling, you can write the data anywhere you want in the array - spreading data evenly over all the chips improves the lifetime of the device anyway.

      So you could use the devices in a round robin schedule so that you can keep the interface fully occupied. And if the interface is really fast and you have a large queue of writes you could imagine all the chips programming at the same time, even if you can only send data to one of them at a time.

      And because you're just clocking data into an SRAM buffer in the device it is possible to imagine much faster synchronous interfaces - DDR SDRAM manages 666 Mhz using both edges of a 333 Mhz clock, and it's not out of the question to have a fast synchronous interface like this to the NAND chips. Not that you need DDR speeds, a 100mhz 8 bit synchronous interface would be enough to keep 20 or so chips fed. And then you'd writing data at 100Mbytes per second, which is not bad even compared to a hard disk.

      Even with present day devices clocked at 25Mhz and a cheap MCP with the data pins bussed you can manage 25Mbytes/sec. Which is much better than the case where you have one chip and need to wait for it to finish programming or erasing. Then you end up only using 1/10th to 1/5th of the available interface speed.

      --
      echo -e 'global _start\n _start:\n mov eax, 2\n int 80h\n jmp _start' > a.asm; nasm a.asm -f elf; ld a.o -o a;
    2. Re:Not parallel by JoelKatz · · Score: 1

      They probably don't do this in such an early chip because, as you suggest, this is intended to demonstrate capacity, not speed. But they can connect all the pins in parallel and minimize the pin count and *still* operate the chips in parallel. There are a number of ways to do this.

      One simple way is for each device to have two 'chain' pins, one for 'in' and one for 'out'. You connect one chip's in to the supply, and then each chip's out to the next chip's in. The last chip's out is grounded. On power up, each chip looks at its in and out pins and figures out where in the sequence it is.

      Then, when you want to write data, you put the last chip's data on the wire, pulse the clock, then the next to last, pulse the clock, and so on. Each chip knows which data it should store and when all the data has been sent, so they all store on the final pulse. For read, they all take the address at once, and then the last chip writes its output, when you send a clock pulse, that chip knows to stop sending its output and the second-to-last knows to start sending its output.

      It can be done even if literally all the pins are connected together if each device has a unique burned-in serial number. There are simple techniques for each chip to detect what other chips it's connected to and to sort themselves into serial number order.

  23. 100,000 write cycles is plenty... by tyme · · Score: 1

    100,000 write cycles is plenty, so long as you buffer the writes and limit their frequency. All you need to do is either put a big honking RAM writeback cache next to the FlashRAM, or enforce writeback caching in the OS. If you can get the write frequency down to about two writes per hour, and do good load leveling, your FlashRAM will last for 5 years, which is about as good as most consumer grade hard disks (and possibly better, since the 'expired' FlashRAM drive could still be perfectly readable). Two writes per hour may sound like a very aggressive goal, but it wouldn't be so hard if you preferred to evict clean pages from cache before dirty pages (which is not so bad, since the read latency of FlashRAM is not nearly as long as that for a spinning platter, so refilling evicted pages is not too expensive).

    --
    just a ghost in the machine.
  24. According to NASA by brunes69 · · Score: 2, Funny

    Hynix, has announced they have stacked 24 flash chips in a 1.4mm thick multi-chip package

    According to NASA, it may even be possible to stack 48 chips in a 2.8mm package. Scientists also speculate someday we may be able to achieve up to 240 chips in a 14mm thick package.

  25. Master Control Program by fear025 · · Score: 1

    Has anyone else wondered, with all of this extra data at its command, how is Tron going to defeat the Master Control Program this time?

  26. 25um thin by Anonymous Coward · · Score: 0

    For anyone interested, 25um thin is VERY impressive for thinning silicon. (and I am a microelectronics package engineer) It's thinner than a sheet of 8x11 paper, and allows the wafer to flex so easily you can literally roll it up like paper. (this is silicon, mind you, which is brittle like glass!)

  27. 48GB MCP? by T-Ranger · · Score: 1

    Wow, and all the graphics were done on a Super Foonly, which had at best a couple of meagbytes.

  28. 1 MiB - 1 MB = wear leveling by tepples · · Score: 1

    though keep in mind that the 48GB might really be 49 or 50* to provide spare sectors in the same manner hard drives do. Based on my experience buying CF and SD cards, this is actually where the 4.8 percent difference between a MB and a MiB goes. When you buy, say, a 512 MB memory card, it is actually a 512 MiB (536 MB) memory card where 4.8 percent of the sectors are spared. I've bought three "1 GB" cards, each of which had 1,024 MB available for files, folders, and allocation data.
  29. Are they really run near the limit? by tepples · · Score: 1

    If your drive is 1% full then you can distribute your writes over the other 99%. But most people don't keep their storage mainly empty. In fact people tend to run just under the limit Citation needed, at least for common uses of flash memory. One common use case for flash memory is in digital cameras. A photographer shoots a "roll", copies everything from the pictures folder on the flash card to a larger drive, and deletes the "roll" from the flash card. Even for larger drives such as hard disk drives, Windows encourages the user to keep 15 percent of the drive free so that Defrag can work more efficiently.
  30. Re:NAND flash writes by Anonymous Coward · · Score: 0

    Whether it might be "ridiculous" or not, for MLC (high capacity) NAND flash, failure rates are such that device lifetime is indeed limited to several thousand (depending on vendor/device) erase/write cycles.

    I don't quite know what you mean by "glorified thumb-drive flash memory" or "high quality construction", but the reality of the situation is that the only NAND flash that is available at competitive prices is at the (cheap, dense) corner of the market, and that's where the Hynix 16Gib die referred to in the story linked above is.

  31. For a moment there by turing_m · · Score: 1

    I thought we were getting a new RPN graphing calculator. Doh.

    --
    If I have seen further it is by stealing the Intellectual Property of giants.
  32. Re:swap space / tmpfs / cacheing (I do that) by Anonymous Coward · · Score: 0

    I use a CENATEK "RocketDrive" Solid-State RamDisk that is on a PCI 2.2 bus & uses PC-133 SDRAM! I have owned it since 2003 & it's STILL running strong (let's see a FLASH based one last 5++ years & still work)!

    There have been FASTER performing units releasing since then (Gigabyte IRAM, uses SATA 150 bus, & DDR2 RAM, & an even FASTER unit is coming in the DDRDrive X1, which uses PCI-Express bus, & DDR RAM (this is THE ONE to look for imo)).

    On mine, I use the 2nd 1gb partition on my SSD for:

    ====

    Webpage Webbrowser caches

    Temp ops (via %TEMP% & %TMP% environment variables/SET statements)

    Logging (Such as EventLogs from the OS, & inside apps themselves like Windows firewall, or ZoneAlarm for example)

    ----

    * EventLogs CAN be moved via registry hacks onto that one by the by:

    SYSTEM LOG:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Servic es\Eventlog\System

    APPLICATION LOG:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Servic es\Eventlog\Application

    SECURITY LOG:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Servic es\Eventlog\Security

    (Check the FILE value in each - then, you will have the actual locations of them AND YOU CAN MOVE THEM!)

    ====

    PLUS - & I use NTFS compressed partitions (this helps, with GOOD reason, read on).

    By using NTFS compression, formatted with 4096 byte sectors (to match cache & read/read ahead mechanisms the filesystem driver uses as its size for this)?

    This acts on text based data on this partition to benefit perfomance in a couple ways:

    1.) Since text compresses FAR above even a 2:1 ratio, my data from temp ops, webpage caches (the HTML stuff) & logging stores excellently, and reads up faster from disk (smaller files) & the NTFS compression stage into RAM is offset excellently by today's fast CPU's + RAM as well...

    2.) And, like the pagefile.sys benefits extolled below? I avoid the fragmentation & clutter that logging, %temp% ops, & webpage caches create, + they access for reuse 1000's of times faster than they would off std. mechanical HDD's... by far!

    3.) I also avoid head movements on my main C: drive this way as well, thus, allowing programs to launch faster since the HDD is not burdened with I/O for head movements for paging, %temp% ops, logging, OR webpage caches!

    ----

    By using NON-NTFS COMPRESSED partitions (for paging) also formatted to 4096 byte sectors (to match read/read-ahead mechanisms in the filesystem PLUS to match how the pagefile.sys is read/wrote)? I get these benefits (for pagefile.sys placement):

    A.) I put my pagefile.sys onto its 1st partition, & it works VERY well this way (taking away the burden of I/O from my main C: drive, in doing paging operations & thus, allowing programs to operate faster because no head movements are in the way doing paging!

    B.) PLUS, I avoid fragmentation of the pagefile.sys itself, + other files too as it grows (or contracts @ bootups).

    ----

    You may be tempted to state "logging takes a speed hit" & yes, it does using NTFS compression especially... you'd be right as rain!

    HOWEVER, this is largely offset by my ability to double or more in storage of log data (due to compression & the fact logs are usually text data which compresses excellently), in the speed of access to the files, AND the fact today's CPU's + RAM are SO FAST, that the compressed writing stage is not as big of a "hit" to performance as it was years ago... vs. today!

    Plus, the ns speed (vs. ms, many orders of magnitude slower speeds of access/reaccess of std. mechanical HDD's) of RAM used on SSD's allows for SUCH fast access/reaccess of files on SSD's, it helps a great deal there too...

    APK

    P.S.=> Anyhow/anyways, how I use mine is much for t

  33. Parallel read unlikely by mako1138 · · Score: 1

    Flash chips have a standard interface: a set of control lines and an 8 or 16 bit address/data bus. In multichip flash packages, each chip is typically mapped to a portion of the address space. This also allows backwards compatibility when the die density eventually doubles. (e.g. I was using some Micron parts where the 4Gb part was a 2x 2Gb MCP. A couple months later and the chip was revised to 1x 4Gb.)

    If you want parallel read, you're going to need a whole lotta pins, and corresponding board area. Whereas the point of the MCP is to reduce pin count and board area. MCPs are for highly integrated devices like cellphones and portable media players, where space is at a premium. The throughput of one Flash chip is sufficient for these applications.

    1. Re:Parallel read unlikely by JoelKatz · · Score: 1

      You do not need a lot of pins or a lot of board area for parallel read. So long as the interface transfer rate exceeds the device's internal speed by a significant amount, you can increase the effective transfer speed without increasing the pin count.

      Basically, each device simply determines where it is in the chain (either by a two-pin series connection or by self-sorting by unique device ID) and ignores the data that isn't for it. So you could, for example, clock 32 units of data for each of 32 physical devices and have each device assert an acknowledge when it's done. By the time you get back to the first device, it's already finished the previous access.

      On power up, each device interrogates the others and determines how many devices are physically present and what device number it is. This can be done in less than a second for dozens of devices and only requires a single data pin and a single clock pin connected together on all devices.

      If there are 32 devices and we are device 2, we simply look at each read or write and if the last 5 bits don't equal 2, we ignore it. A device acknowledges an operation as soon as it has started it and needs room to hold the next operation and an operation in progress. This way, sequential reads and writes will go to all 32 devices in rotation, allowing a device to acknowledge an operation immediately, since it has already finished the preceding access to it (31 accesses ago).

      This is very simple, well understood, and permits large numbers of devices to operate concurrently even with all their pins connected in parallel and without a large number of extra pins for coordination.

      It only works, however, when the interconnection between devices is several times faster than a single device's transfer rate. This is the case for most flash devices.

    2. Re:Parallel read unlikely by mako1138 · · Score: 1

      I'm talking about existing/realistic parts. Certainly you can put everything on a bus. That's obvious. But a bus within an MCP? I doubt that Hynix would go through all the effort to create what amounts to a memory controller when they can just add a mux to the existing logic.

  34. Re:NAND flash writes by fractoid · · Score: 1

    ...but decent chips with good wear leveling and high quality construction. Pardon my ignorance, but wouldn't the number of writes to any given cell be independent from any wear leveling? That is, unless you're talking about writes to the device as a whole, at which point the point becomes moot because you can decrease the duty cycle arbitrarily by adding more redundant memory.

    As for write cycles possible, while probably not the most authoritative of resources, wiki says:

    The endurance of NAND flash is much greater than that of NOR flash (typically 1,000,000 cycles vs. 100,000 cycles). This is because programming and erasure in NOR flash rely on different microscopic processes (hot electron injection and quantum tunneling, respectively), while they are perfectly symmetric in NAND flash (Fowler-Nordheim tunneling). [5] The asymmetric nature of NOR flash programming and erasure increases the rate at which memory cells degrade, over many program/erase cycles.

    The superior symmetric programming method of NAND flash has in fact been adopted in many NOR flash designs, so that some modern NOR chips boast endurance comparable to NAND flash. [5] (pp 5-7)
    --
    Rampant carbon sequestration destroyed the Dinosaurs' tropical paradise. I'm here to help repair the damage.
  35. Take over tape, not hard drives by guruevi · · Score: 1

    I personally think flash memory is going to take over from traditional backup tapes, not hard drives. The problem seems to be writability and that might be a physical problem. If however, we get to build 48GB cartridges they come pretty close to small business backup tapes. Flash drives are very portable like tapes while hard drives are very 'sensitive' to shocks and other external factors.

    --
    Custom electronics and digital signage for your business: www.evcircuits.com
    1. Re:Take over tape, not hard drives by WuphonsReach · · Score: 1

      I personally think flash memory is going to take over from traditional backup tapes, not hard drives. The problem seems to be writability and that might be a physical problem. If however, we get to build 48GB cartridges they come pretty close to small business backup tapes. Flash drives are very portable like tapes while hard drives are very 'sensitive' to shocks and other external factors.

      Interesting idea... the 4GB SD cards are almost dirt cheap now (less then $40?) and there are 8GB SDHC cards already in channel (~$80) with 16/32GB cards coming soon. However, I think the magic size is probably going to be 128GB for $100-$150 before they'll knock off low-end tape. That would make the 64GB chips around $50.

      Still, you're right that flash memory is extremely dense and reliable compared to traditional tape.

      --
      Wolde you bothe eate your cake, and have your cake?