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Hard Drive of the Future: Ram Drive

benzick writes "3d Retreat has posted a hands on look at a 2gig ram drive called the Rocket Drive. Article blurb: Overall the rocket drive is the best in I/O performance I have seen. It outperforms U160 SCSI drives by almost a factor of two. Yet there are some drawbacks to the Rocket drive, foremost is the price, although listed at the end of the review is some alternative pricing options to make it less expensive. And the rocket drive can not act as a boot drive. Also, if you have some extra money to spend, you can use multiple rocket drives in parallel."

60 of 397 comments (clear)

  1. Re:x10^2?! by biggknifeparty · · Score: 3, Informative

    Product: Rocket Drive (2 gig)
    Manufacturer: Cenatek
    Web site: Product Information
    Price (MSRP): $2,999 (as tested)
    Release Date: Available Now

  2. Re:Huh? by Trusty+Penfold · · Score: 4, Insightful

    It's another bullshit "hardware site" test.

    The "benchmark" was a Photoshop filter on an image. It was twice as fast as with the SCSI disk.

    This tells you very little about the relative performance of the drives since image processing is typically not disk bound.

  3. Re:x10^2?! by mstyne · · Score: 4, Funny

    For that price, I'll wait the extra 7 seconds for Mozilla to load, thankyouverymuch.

    --
    mstyne: real name, no gimmicks
  4. External Power Cord!?! by cscx · · Score: 5, Insightful

    And if someone trips over the cable, there goes your 2 gigs of data!

    Thanks, but no thanks, I'll stick with mah good ole Winchester disks.

    1. Re:External Power Cord!?! by AllTom · · Score: 3, Insightful

      The first thing that I thought of when I read the headline after, "hmm, interesting," was, "What?? RAM for storing data?"

      I've had problems enough with hard drives crashing and losing data without having to worry about having a power outage and losing everything. A UPS is a good idea for servers, and perhaps in some other special incidences too, but I wouldn't want to be tied down to having one. The electricity to my house is rarely constant, and lights flicker all the time due to lackluster electrical jobs.

      For me at least, 2 GB is not nearly enough to store all of my data anyway. If they find a way to assure me that I won't lose my data, and increase the size of the drive, then I may just opt for the enhanced speed. Until then, I'll stick with my current drive.

  5. GOOD! by NineNine · · Score: 5, Insightful

    The hard drive is some ancient technology that is the *easily* #1 cause of all computer failures. Other than the cooling fans, they're the last moving parts, and the most critical ones too... A fan dying may cook your computer, but a hard drive kills your *data*. It's high time that something came along to replace those damn things. I'm typing this on my PC with a 2 drive RAID because I can't afford downtime or data loss. That really shouldn't be necessary any more. Bring on the alternatives!

  6. Yes, but this one ... by Tensor · · Score: 5, Informative

    Keeps that data after the pc is turned off, which i bet your amstrad didn't do.

    It has an external supply that keeps the card powered.

    And i believe this is the whole point of this card, its pretty much useless otherwise.

    Also the xfer speeds are limited to PCI (66mhz) speeds, that is why "its only" 2x as fast as a U160 scsi.

  7. Why this beats a traditional ram drive. by lavaforge · · Score: 4, Informative

    This is really pretty interesting. The device has it's own power supply that actually allows you to save data when you shut down your computer. It doesn't seem like it would be too reliable, but it does provide a reason as to why this is better than a traditional RAM drive (provided you have it hooked up to a UPS).

    1. Re:Why this beats a traditional ram drive. by nuggz · · Score: 3, Insightful

      I don't reboot my computer, might as well have a ram drive. Heck with something like tmpfs being able to swap out it would be MUCH better.

      All we need is motherboards that accept more then a gig or two of memory.

    2. Re:Why this beats a traditional ram drive. by _ph1ux_ · · Score: 3, Insightful

      ya but does it ahve an external power adapter you plug into the wall - or a battery on it?

      Try moving to another machine with 2GB still alive on this thing...

      Although a really good application for this would be that guy running the game cluster - or any game for that matter.

      Run the whole game in the ram drive, everything, including the movies. Talk about speed.

  8. Not practical by selectspec · · Score: 4, Insightful

    1. A DRAM "drive" suffers the fundemental problem that if the "external" power source is lost, you lose everything on the drive.

    2. 80-100 MB/sec sustained performance is nothing to write home about for DRAM performance. A RAID 0 stripe across 2 ATA drives could give you this same performance for about 1/4 the price without the power issue.

    Although its a long way off, MRAM offers a much more promissing application in the area of high speed RAM drives.

    --

    Someone you trust is one of us.

    1. Re:Not practical by delta407 · · Score: 3, Insightful
      A DRAM "drive" suffers the fundemental problem that if the "external" power source is lost, you lose everything on the drive.
      This raises the question as to why they didn't integrate a rechargable battery, sort of like an internal UPS, that would take system power when available and then give just enough juice to keep the RAM powered for, say, 24 hours of downtime. Such a drive would only really be useful in a high-performance server anyway, which is likely not to have 24 hours without power.
      A RAID 0 stripe across 2 ATA drives could give you this same performance for about 1/4 the price without the power issue.
      Yes, but then you have other issues -- heat, noise, and moving parts. Hard drives are far more prone to hardware failure than RAM is.
    2. Re:Not practical by Ed+Avis · · Score: 3, Insightful

      I suppose a good use of this is it may support much more RAM than you can get on the motherboard. You might have six PCI slots - filling each one of those with a RAM drive gets say 12 gigabytes of extra RAM or at least extremely fast swap space. With four DIMM sockets (which most motherboards don't have AFAIK) it would be hard to get more than 4 gigabytes on the motherboard.

      OTOH, if you have such large memory requirements you'd probably be using some serious 64-bit hardware and not Intel-based toys.

      --
      -- Ed Avis ed@membled.com
    3. Re:Not practical by selectspec · · Score: 3, Interesting

      To be fair of course, DRAM drives do offer the following features and are used as "caches" in many large server farms (like google, ebay, etc):

      1. DRAM drives suffer no penalty to random i/o workloads while disks even in RAID configurations do suffer penalties.

      2. DRAM drives export a larger addressable cache area, extending main memory. Throw a couple of these 4 GB modules into your server, and you have essentially extended the cachable address space beyond the 4GB limit of 32-bit CPUs to 16GBs + 4 GB of main memory. For web farm servers this is a nice feature that can be cost effective.

      However, in no way should DRAM disks be confused with real drives, where persistence of data is truely important. For example, most RAM drives don't even bother with an external power cable.

      --

      Someone you trust is one of us.

    4. Re:Not practical by Ed+Avis · · Score: 4, Informative

      On the first-generation IBM PS/2s, the amount of ram on the motherboard (or in IBM-speak 'planar') was limited, with more added by plugging cards into the MCA bus. I have a Model 80 which has only eight megabytes on the motherboard but another 32 on a Kingston MCA card. Back then, RAM speeds were a lot slower and the new bus was fast - memory on the expansion card is only about twice as slow as that on the motherboard. (I haven't yet found a way of persuading Linux of this fact, I would prefer the kernel to use the lower eight megs preferentially.)

      There was even a feature called 'matched memory cycles' in the very early machines where the MCA bus would be temporarily underclocked when accessing memory so that it could work synchronously (cutting some wait states). But then the increasing speed of RAM and the fairly constant bus speed (MCA was 32 bits wide at 10MHz, standard PCI not that much better at 33MHz, while RAM access times have gone down hugely from 85ns to goodness knows what) made the idea look silly, and IBM abandonded MCA-bus memory cards for its second-generation models in 1992 or so. Nowadays you could never get away with using something so slow as the PCI bus for 'memory', so it has to be marketed as 'RAM disk'.

      --
      -- Ed Avis ed@membled.com
    5. Re:Not practical by addaon · · Score: 3, Interesting

      Exactly. And by using it as a 'ram disk' you're giving up the huge advantage that ram has, while not decreasing the cost much. I mean, if this system used 70ns ram, it would be just as fast given bus limitations, but much cheaper... cheaper, that is, if anyone made 70ns ram any more. What it comes down to is that if we want radical ideas like this to be feasible (and this is a radical idea, in the sense that no one thought about it when deciding the current pc architecture), we need a lot more flexibility in how systems are designed. I was recently working on a random number generator in hardware for crypto purposes, and the pci bus simply didn't have enough bandwidth, so we ended up fitting an fpga into a memory slot, the exact opposite of what this ramdisk is doing. What we need is direct access to the memory bus itself through some connector (or better yet, to the hypertransport bus between the cpu and the memory controller), which would allow devices like the ram disk, or simply ram cards like you describe, to work with the current pc architecture. Timing on such a bus would be a bitch, but you could assume it remains unused except for systems with truly special needs.

      --

      I've had this sig for three days.
  9. What's new? by p3d0 · · Score: 5, Interesting
    You hear about ramdrives every six months or so. It never amounts to anything. I don't see why this would be any different.

    Fundamentally, you're always better just to use caching. Essentially, this amounts to a 2GB dedicated disk cache, except that the power supply ensures that the contents survive boots (though I don't know how it would do in a power failure). Anyway, how often do people reboot their machines nowadays? Stuff stays in my computer's cache for months at a time.

    So, why not just add the 2GB to your main RAM? Then the OS could use it as a disk cache if it were so inclined (and you'd be right where you are with a ramdrive) or else the OS could use it as actual RAM if you needed it.

    In short, RAM is just like a ramdrive except more flexible.

    --
    Patrick Doyle
    I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
  10. Can I use it for swap? by Thalia · · Score: 5, Funny
    Makes me wonder if I can use for my swap drive;
    1. The OS wants to store something in RAM, trys to allocate RAM and fails.
    2. The OS decides to swap out some memory based on an analysis of page usage statistics, so it grabs the handle to the swap file.
    3. Then, the OS streams the offending pages through file I/O subsystem, worrying about waits and updating page counters and such. This includes dragging all the data over a busy system bus.
    4. The receiving device stores it in RAM.
    Cool! What operating system could aspire to such levels of efficiency?
  11. How This Works... Neat Facts by clinko · · Score: 4, Interesting

    Here's some neat facts. No real solution though. Reply with one if you have it...

    Ram = Fast
    Cache = faster ram
    On Board Cache = faster

    1. Processors used to not have a quick way to get to ram so cache was created (faster and expensive ram) and put on a chip.

    2. Cache proved to be too expensive so they put it off the chips (pII)'s. Celereon's even took off some of the Cache.

    3. Now that ram drives will be created, it's just another link in the chain to the HD.

    now it'll be:

    HD->Ramdrive->Ram->off chip cache->onboard cache

    Each one of those levels cost more as you move to the right. This just puts another link in the chain.

  12. Re:Of the future? by nicuss · · Score: 3, Insightful
    Nope, it's not of the future. The HDD future belongs to something else: platter-level RAID systems. That is, you make a RAID with each head/platter being one unit. It has been tried in the past, but the problem was that the heads would get slightly misaligned in time and you'd have to reformat too often. I think that with the current technology it should be possible to decrease the data density (which is ok now) and use a stronger recording signal (fatter tracks) to allow for some head alignment change.

    Once you do this then ALL heads will be able to read or write simultaneously (in parallel) rather than one at a time as they do now.

    Only question is -- how long till they decide to go for it.

  13. Not limited to 2 GB by delta407 · · Score: 5, Informative

    The official website lists the capacity as 4 GB.

  14. RAM disk vs RAM drive by ThogScully · · Score: 3, Informative

    I know this article doesn't exactly seem to be chock full of information, but the comments can at least be intelligent.

    This is different from using a RAM disk and just using RAM for a disk drive. A RAM drive can actually store information - which is something that RAM disks, which aren't really storage devices at all, cannot do.

    This even means you can store stuff and it's still gonna be there when you reboot. Although, granted, this isn't exactly new technology. I remember talking with a company at Internet World probably 6 or 7 years ago that sold these things to big companies with deep wallets.

    --
    I've nothing to say here...
  15. Re:Good for Mozilla by Jedi+Alec · · Score: 3, Interesting

    The trick is not to put something on it that remains constant, but something that changes all the time. So instead of the actual browser, dump the cache on it. Tell your OS and software to use the drive for temporary storage(swapfile for example) and then you'll get the most out of it. Something the article does not specify but which my software driven Ramdrive allows me to do is to actually load a disk image into the drive on bootup, allowing you for example to permanently install an entire piece of software on it permanently which will then only have to be loaded from the harddrive once...

    --

    People replying to my sig annoy me. That's why I change it all the time.
  16. $2,999 for 2 gigs of Ram??? by frovingslosh · · Score: 3, Interesting
    1440 born a day, equally spaced.

    That's an absurd price for what little there is to be gained from this. Clearly the cash would be better spent on a new MB with an extra 2 gig on it - it could be used as a ram disk if you really wanted, or as a cache, or for any number of uses beyond a silly-cone hard drive. Better to be able to deal with the memory as memory than memory pretending to be disk. And for a lot less money.

    --
    I'm an American. I love this country and the freedoms that we used to have.
  17. The future that already was by jasonditz · · Score: 3, Funny

    That's great, but am I the only one who remembers having RAMdisks on my Atari 800?

    Axlon used to make 128 KB Ramdisks, now that was power!

  18. According to the article... by myov · · Score: 4, Informative

    The bios is set so you can only put in the amount of memory that was specified by the card. So If I purchased the 2Gig empty card. My only option is to put in 4 sticks of 512 pc133 memory. If I wanted to upgrade my card to 4gig. I would have to pay for an upgrade, and then replace all the sticks of memory with 1024Meg sticks.

    --
    I use Macs to up my productivity, so up yours Microsoft!
  19. PCI bottleneck by Door-opening+Fascist · · Score: 4, Insightful

    The article mentions that multiple RocketDrives could be used in parallel. That would seem only to be practical on 64-bit PCI buses. One RocketDrive transfers 80MB/s, which is close to the maximum sustained bandwidth for 32-bit 33MHz PCI. 132MB/s is the burst bandwidth, and cannot be sustained for very long.

    In fact, I would think this drive would interfere with other devices that rely on the PCI bus. I doubt you could get 100Mbps (~12.5MB/s) on the same PCI bus.

  20. POWER SUPPLY by Stoutlimb · · Score: 3, Informative

    Wasn't there just a slashdot story a while ago saying how it was Power supplies that were the huge cause?

  21. Re:How This Works... Neat Facts by Fluffy+the+Cat · · Score: 4, Interesting

    HD->Ramdrive->Ram->off chip cache->onboard cache

    Each one of those levels cost more as you move to the right. This just puts another link in the chain.


    Sure about that? For the price of the Ramdrive, I could easily get 2GB of DDR. Hell, for the price of the Ramdrive I could get a motherboard that supported 64GB and fill a moderate chunk of it. That thing has lower speed and greater access time than main memory and costs more, so just using RAM as disk cache would appear to be more useful under the majority of circumstances.

  22. Re:Huh? by at_18 · · Score: 5, Informative

    This tells you very little about the relative performance of the drives since image processing is typically not disk bound.

    Actually, the author of the article made it disk bound, by forcing Photoshop to go into swap space with an image much larger than the available memory.
    And you missed the HD testing pictures, measuring high throughput (sp?) and unbelievable low latency.

  23. More work soulda been put into this card by Tensor · · Score: 5, Interesting

    If these guys had made this compatible with scsi, like emulating a scsi card and 1 device, so it could boot it would rock.

    From power off to up and runnig in seconds !

    This would be ideal to store an OS, even for a server, and have the HDs configured to copy the os back to the card and reboot in case it fails to boot from the card for some reason ...

    Hook the power source to a ups and you can probably keep the info for more than a week without external power should you need. (i mean, how much juice can this need?)

  24. Missing the Point by locarecords.com · · Score: 5, Interesting
    I think you are all missing the point somewhat...

    What if you could boot from this drive? If it were Flash Ram then presumably you could store your operating system on a RAM Drive and get it to boot instantly cutting down on the boring and annoying wait for the computer to start up.

    Another drive could be used for storing files and such like (if it were thought to be somewhat dangerous medium to *store*) but in anycase it would be lovely to get instantly booting computers.

    In addition, rather than booting, couldn't these drives make possible a kind-of ghost-like save boot-up state. ie Copy into memory very quickly the state of the computer just following boot up. Now that would surely speed up the booting process.

    And I know everyone might say, oh that doesn't matter, but even though I use a Powerbook which with OS X stays up almost forever - I *still* need to boot occassionally. And it is *painful* to wait for.

    Once it is built into my laptop I will be well happy... I hate chugging drives... and silence is golden

    --
    ---- The Open Source Record Label : : LOCARECORDS.COM
  25. Sustained Performance vs. Latency by morzel · · Score: 5, Insightful

    "Sustained performance" is only a practical measure in a few uses (eg: multimedia). For most other things, latency (ie: seek times) has a far greater impact on performance. Even the fastest harddrives have seek times measured in milliseconds. With DRAM we're talking about nanoseconds.
    The fundamental problem of "power is lost" can be solved easily by adding a battery on the drive.

    --
    Okay... I'll do the stupid things first, then you shy people follow.
    [Zappa]
    1. Re:Sustained Performance vs. Latency by Babbster · · Score: 3, Insightful
      The fundamental problem of "power is lost" can be solved easily by adding a battery on the drive.

      Isn't that "fundamental problem" already solved by plugging any important computer into a UPS? I think we can safely assume that anyone spending $3,000 on a RAM drive would consider their computer important enough to be on a UPS into which, presumably, this device would also be plugged.

  26. Some people can't afford ($) not to reboot by yerricde · · Score: 5, Funny

    Anyway, how often do people reboot their machines nowadays?

    I'll answer the related question, "why would anybody need to reboot a computer?"

    Some slashdot readers are lucky enough to live and work in an environment that primarily uses BSD or Linux. But unlike some slashdot readers, I, Damian Yerrick, live and work in an environment that primarily uses Microsoft Windows. Therefore, I have to use Microsoft Windows.

    Some slashdot readers are lucky enough to be able to afford personal copies of PC virtualization software such as VMware, so that they can run other operating systems within a window on their computer. But unlike some slashdot readers, I, Damian Yerrick, can't afford a VMware license. Therefore, I must run Microsoft Windows on the bare hardware, and if I want to run an operating system other than Microsoft Windows, I must reboot my computer to access it.

    Some slashdot readers are lucky enough to be able to afford to buy additional hardware to shield their other computer from exploits of newly discovered vulnerabilities in its operating system. But unlike some slashdot readers, I, Damian Yerrick, can't afford a second motherboard, CPU, case, and keyboard on which to run BSD firewall software. Therefore, if I want to keep my computer connected to the network, I must keep my computer updated with patches from Microsoft Windows Update. Those patches often require a reboot of the computer.

    Therefore, I, Damian Yerrick, cannot afford to own a computer system that does not have to be rebooted.

    --
    Will I retire or break 10K?
  27. Security by denisonbigred · · Score: 5, Interesting

    Most people complain about how this drive or RAM disks are completely wiped out by a power loss, but couldnt that also be used as a great security feature. If you have alot of data that you dont want someone (read: The Government) getting their hands on or taking as evidence, just keep it on a drive protected by a UPS, then if you need to wipe it out quickly and completely, just pull the plug. Or if a few lovely FBI agents come and take your computer, they do it for you.

    --

    "There's no way to rule innocent men. The only power any government has is the power to crack down on criminals."
    1. Re:Security by vranash · · Score: 3, Informative

      You must've missed the article on here a few months/year back about the guy (@ MIT?) that was disassembling RAM and able to find the 'most used position' of transistors to recover data out of memory, similiar to how they can do it from mechanical hard drives if not completely wiped.

  28. Cache should be expandable on hard drives by DarkHelmet · · Score: 4, Insightful

    This is just sad...

    3,000 dollars for something that has 2 gig of ram. I could get 2 gig of ram for a fraction of that amount... In fact, for the speed its giving, I could fill the thing up with sdram or edo ram...

    This is something I could imagine being useful with my hard drive... Why don't they make a standard plugin for hard drives... Make it where you can add cache directly to the hard drive.

    But wouldn't it be better to just have RAM instead of this?

    Not if you're going to go over 4 gig. You'd then need a 64 bit solution for that... If, on the other hand, you could add MAJOR amounts of cache to your hard drive, it wouldn't matter if you only had 4 gig of actual memory. You could run IA-32 as long as you like. You could have potentially gigantic databases without worrying as much about disk thrashing...

    It's going to be potentially a long time until a 64 bit winner in the PC world is declared... As time goes on, something like this may actually be viable. And as memory prices go down, we're going to be seeing a lot more 4 gig systems around...

    Or am I on crack?

    --
    /^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$/i
  29. Swap space?? by Chanc_Gorkon · · Score: 3, Interesting

    Could one use this for swap space? Swap could be regenerated between power off (say when you move the machine). Then you could have a startup script see if this thing was configged on boot up and if it was, use the swap. If not, it could config it as swap and then reboot? Am I off base here? Swaps would be lightening fast and if you happen to lose swap when powered off it ain't no big deal.

    --

    Gorkman

  30. Another example of military technology trickle dow by t0qer · · Score: 5, Interesting

    n.

    Most modern Fighter jets use ramdrives exclusively because the high-G manuvers, shaking, ect would cause a normal drives heads to go smashing into the platters. I know the B2-stealth has some, so does the F-16.

    When you're the goverment, and you want reliable killing machines, 250k for a 250meg ram drive back in 1987 isn't even an afterthought. It's a requirement. Now that it's dirt cheap to produce memory, it can finally trickle down in price enough to have become feasable for a civilian to afford one.

    I know originally the early drives were used to hold map data for the HUD, which was basically just the data gained from our digital elevation modeling sattelites launched in the 80's. Given the advances in 3d modeling and sattelite map aquisition, I would guess whatever system they're using today probably contains terrabytes of map data.

    I'm sure the old green vector graphic huds have been replaced with something a lot better to utilize the new data too. I'd suspect that in the actual control area there must be a LCD display, much like what you see on a modern 737.

    It must be one helluva video game for them pilots :)

  31. PCI Problems by GoRK · · Score: 3, Insightful

    As others have pointed out, this 32 bit PCI card pretty much sucks. It outperforms, what, a single U160 drive on a 32 bit controller? By only a factor of two?!?

    You could easily smash the performance with a little U160 RAID on a 64 bit pci controller, and perhaps even with a single drive, though seek time would hurt a bit. At least it'd cost you a hell of a lot less.

    It's not battery backed either, which is pretty useless for anything this might need to do. Heck, without battery backup, it proabbly can't even survive a reboot to get that precious data back after a system crash!

    This reeks of an EE or Embedded Systems course assignment. It's barely a real product.

  32. Re:What's the point? by vlad_petric · · Score: 4, Insightful
    Well, in the world of architecture, small is fast and large is slow. Memory is already an order of magnitude slower than the CPU.

    Furthermore, RAM drives are really meant for servers. Such a server will most likely use a fast internal memory (like RAMBUS) and cheaper, slower & much larger SDRAM 100 for the RAM drive.

    The Raven.

    --

    The Raven

  33. Re:Swap FIle by 7-Vodka · · Score: 3, Informative
    I'd have a hard time justifying spending $3000.00 for that thing as a swap file. My system has 1 gig of ram and never ever hit's swap. It's faster this way because my system ram doesn't have to go through the pci bottleneck.

    I would buy extra ram instead of this rocketdrive. The bandwidth of my system ram is 2.1GB/s. This rocketdrive benchmarks at 78MB/s.

    --

    Liberty.

  34. Solid State Drive by AtariDatacenter · · Score: 5, Interesting

    I've had the pleasure of playing with RAM based storage devices at work. They're a lot of fun. The particular models we used were external, SCSI, memory based, with a battery backup and internal disk for long-term storage.

    The nice thing is that they can drive as many reads/writes as you can get out of the SCSI channel. Seek time isn't a factor at all. We're talking disk performance through the roof here! There are also UltraSCSI and other types that'll go even faster. But the only real limitation is the link between the drive and the computer.

    Still, the data rate doesn't approach what this PCI based solution has going. But what I use is a more 'enterprise' solution. You've got internal battery backup and disk backup. If the unit is off the mains, the battery kicks in. After 30 minutes, it stops all IO, dumps to disk, and shuts off. When power is restored, it loads back in from disk.

    This PCI solution is way cheaper than the external drives that I've used. Just it doesn't appear to have the reliability... or the commodity standards that'll let it hook up to just about any type of system. Still, quite neat!

  35. Useful as the ext3 journal by Illusion · · Score: 5, Informative
    If this had Linux drivers, it would be terribly useful for an external ext3 journal.

    While profiling a high-volume qmail server with fast mirrored drives, I noticed that I could get at least an order of magnitude sustained mail throughput by eliminating the fsync() system call, which essentially forces the disk subsystem to stop whatever else its doing and get a few specific blocks all the way onto disk. You can't run it in production this way, as the SMTP RFC specifies that the mail must be actually on disk before the server can claim that its done.

    The problem is that magnetic-media drives can only seek a few hundred times per second. Regardless of their claimed sustained throughput, if you are writing a bunch of small files to disk, you are completely dependent on the seek time of the drive.

    But mounting a magnetic-media-based ext3 with data=journal and the journal on an NVRAM block device would essentially use this as a trusted write-cache. Linux will return from the fsync() system call as soon as the data is in the journal, which could happen instantly on an NVRAM disk as there is no seek time. It then reads from the journal in its spare time, sorts it to minimize seeks, and writes the data out to disk.

    I suspect that this should offer roughly the same speed as eliminating the fsync()s entirely.

    I was looking into ordering a similar product to test this. I found:

    --

    Aaron

  36. Re:Good for Mozilla by TheOnlyCoolTim · · Score: 4, Insightful

    Putting your swapfile on this doesn't make much sense. You'd be buying memory, putting it in a special card that makes the memory act like a hard drive, then making that hard drive act like memory. It would be cheaper to just buy more regular memory.

    Tim

    --
    Omnia vestra castrorum habetur nobis.
  37. Re:Good for Mozilla by jonbrewer · · Score: 3, Interesting

    Something the article does not specify but which my software driven Ramdrive allows me to do is to actually load a disk image into the drive on bootup

    You wouldn't be so kind as to reply with a link to said software ram drive?

    I used this trick on my PowerMac 7100 back in the day, having loaded it up with 136MB ram, an insane amount for 1996... I used to run Marathon off the built-in System 7.5 software ramdisk. :-)

  38. Re:How This Works... Neat Facts by rodgerd · · Score: 3, Informative

    Any Xeon motherboard. Not all x86 OSes support the Xeon addressing model, and it's a segmented addressing system that still restricts you to 4 GB chunks per process.

  39. Been there, done that, got the T-shirt by anonymous+cupboard · · Score: 3, Interesting
    Sorry, I was working with RAM drives 10 years ago. They are neat but expensive and somewhat more limited in their capacity. However, I can say with these things to store their hot files on, the world's largest electronic derivatives wouldn't be able to cope with the load that it does.

    The point is that with the drives that I have used (SCSI-U2W through fibre channel) is that they used good old fashioned interfaces which meant that they were plug compatible with older hardware.

  40. If i were you i would wait for MRAM by cybercomm · · Score: 3, Interesting

    I mean, with this type of technology i believe any geek would feel a **bit** insecure, for if the power supply to those rams goes out, you are doomed. I believe that the only benefits of this type of technology right no are UBER fast seek imes and R/W times. IBM is about 2 years away from producing a fully functional MRAM drive (i believe that they do have sa coulpe of prototypes now that work but their R/W times are absolutley horrendous) that will need no power to store data (once it is written that is). The other alternative would be to have some sort of internal RAID HDD with each platter (or side of the platter) accting as one independent unit, i believe ths may have been tried before, but there have been some problems with synchronisation? (anyone knows more about hat one?)

    --
    Live for the present, learn from the past, and dream of the future!
  41. Blah that's silly by photon317 · · Score: 3, Interesting


    If you're willing to fork out the money, there's several manufacturers who have been puttng out genuine static ram drives for a while. They have microsecond access times, sizes up to 80-ish GB last I saw, IDE and SCSI interfaces, and can have sustained bandwidths limited only by the bus speed. They also consume less power, generate less heat, and don't fail as often because there's no moving parts. They solved the limited write cycle problem by having the drive logic remap blocks of data to spread the write wear around the drive.
    FOr a bleeding edge example, check out E-DISK's soon-to-be-available Ultra320 drive (they're released other similar drives before, just not at this performance level):

    Size: up to 155GB
    Access time: 33-48 us (microsecond)
    IOPS: 9500 - 50000 per second
    Burst data rate: 320 MBps
    Sustained data rate: 230 MBps
    Full Erase (Security feature, press a button): around 26 seconds.
    ECC error correction, MTBF around 2 million hours, 10 year data integrity.
    Write life-cycle of in excess of 100 years at 100 GB of writes per day.

    --
    11*43+456^2
  42. This is new? by r2ravens · · Score: 3, Interesting

    At Comdex, a long time ago (maybe as much as 10 years), I stopped by a booth that had this wonderful new technology - an external hard drive which was made entirely of RAM! Current hard drive quantities of RAM(don't remember the exact capacity, but it was significant.) And it was only $15,000 (comparable drive space at the time was one tenth the price.) Wow! (Ok, sarcasm off)

    I asked that man what would happen if the power was lost. He said that the box had a battery and a hard drive of the RAM capacity inside. If the power was lost, the battery would power it long enough to write all the data to the hard drive. I asked what the advantage was over a regular hard drive. He said access speed and no moving parts. Ok, great benefit, but it didn't seem the value was there for 10x the cost of a drive itself. Anyone remember this?

    I started waiting years ago for someone to come up with a board where I could plug in all those 256k, 30 pin SIMMs that we took out of the Mac Plus' when we upgraded them to 4 MB of memory so I could use them for storage. Never happened (that I know). Now I'm waiting for the same thing for this ever mounting stack of 4, 8, 16 and even 32MB, 72 pin SIMMs.

    Where is the real innovation? I mean, our favored OS here can run well on all this old hardware - 486 and the like, but where are the little trinkets for us cheap SOB's like me? I just want a 5 1/4 external case with a 25 pin D connector that will connect to my SCSI card. The board inside should have jillions of 72 pin SIMM sockets (in pairs is ok, multi-level board is ok) and a connector for an old ATAPI 2 or 3 Gig laptop drive. The case should have room for a little battery to do what that really expensive drive could do years ago to backup in case of a power failure. Hell, I'd even pay 50 bucks or so for it. Any takers?

    I'm not an EE so I'm not up to making it myself, but someone out there would consider it a fun project...

    You know, reuse, recycle, make the world a better place. I don't want to have to throw out all this memory or sell it for a quarter a stick. I guess I could use the dremel tool, drill little holes in them and make geek earrings, but I don't wanna have to do that either.

    If anyone has any ideas, lemme know. :)

    BTW, no need to call me a cheap SOB luddite, I already did that...

    --
    War is Peace. Freedom is Slavery. Ignorance is Strength. - George Orwell or George Bush?
  43. Re:RAM drives are stupid by ComputerSlicer23 · · Score: 5, Interesting
    Effectively, in the proper configuration on a Linux machine, this could significantly speed up certain specific operations.

    First off, run ext3 and put all of journal log file on. Poof, now you got a disk that has no latency pently for syncing the data. It will reliable be there when you reboot, so if you crash the log file is still there. You know all those benchmarks that Moshe Bar does where he turns off fsync() so he can push the CPU and memory to it's limits instead of the disk. He wouldn't have to do that so much any more.

    Some Oracle DBA's would trade their soul to get Oracle's transaction logs written to something like this. A drive that has no latency is very, very good. No it's not as fast as RAM because it's behind a PCI bus, but in a lot of ways, no latecy permanent storage is the holy grail to a lot of problems.

    If filesystems and OS's supported this, it's like getting a very flexible configuration for very high end SCSI cards. You know those really highend SCSI cards that have battery backed up RAM in them? The ones that sit behind that pokey SCSI bus? By putting the no latecy storage out in a place where you can get your hands on it w/ OS tools, you can custom configure it just the way you need it. You can upgrade it, you can add more. You can do a lot of things with this, that are much more flexible then any SCSI card will let you set up.

    No they aren't the end all be all of permanent storage, however they have very specific usages, in specific high end situations that make them extremely valuable. If this one doesn't have an internal battery that can hold it's contents for say 400 hours without power, I'm not terribly interested, but as soon as it can do that without external power, I'd pay for it in a heartbeat for the Database servers and the high performance filesystems we run at work. A number of the ext3 people have talked deployment of devices like this will really improve the performance of a number of filesystems.

    Kirby

  44. It's RANDOM I/O that's implortant by walt-sjc · · Score: 3

    Oh please. Encoding of a serial stream has ZERO need for really fast I/O. All you need is a normal drive that has a high enough sustained transfer rate to handle the stream. Any normal hard drive is up to the task.

    Think of applications that need to randomly access the drive. Think web servers, caching proxies, databases, etc. We had a custom app that needed to write to around 40,000 files simultainiously, and read from them randomly. The only feasable solution was a rather large RAM drive system. The one we used was external, had it's own hard drive for backing up the image, UPS, etc., hooked up to the normal SCSI bus, and cost around $12K for a 2G box (this was a number of years ago when RAM was much more expensive).

    Nice thing was NO DRIVERS. It was a SCSI drive to the OS. You could boot off it if you wanted to.

    Soliddata.com in case you are wondering.

  45. Re:Good for Mozilla by Feanturi · · Score: 3, Insightful

    Putting your swapfile on this doesn't make much sense. You'd be buying memory, putting it in a special card that makes the memory act like a hard drive, then making that hard drive act like memory. It would be cheaper to just buy more regular memory.

    Except that you can have memory from here to the moon, yet Windows and various programs running on it will still insist on using disk-based virtual memory anyhow. With XP, setting the pagefile to 0 MB for all drives tends to work for awhile, and through several reboots, but then suddenly Windows will pick a drive and make a 1.5G (the same as the physical memory in my box) pagefile there, without telling me. It only does that if I had it at 0. If I have set some other value, like 512, that will stick. My system has over a gig physical free most of the time, yet still has about 150MB or so allocated as paged. This device turns that stupid problem into nothing, voila! I want it bootable before I will buy one, but I can't wait to have one and point all my apps' temp folders at it, like Cool Edit and such, that would be mega-sweet. Getting to set a nice big pagefile on it as well would be a nice bonus, as Windows could leave me the hell alone about such issues and I wouldn't care that it was being used needlessly.

  46. Pricing Sucks by SQL+Error · · Score: 4, Insightful

    This is potentially interesting, but there are several problems:

    1. The pricing model sucks. The entry price of $399 is too high for a card with one chip and four DIMM sockets. And that only supports 512MB. To go to 1GB, 2GB or 4GB you have to pay hundreds of dollars more - even though the only change is a BIOS setting.

    2. The RAM pricing is absurd. These guys need a reality check, pronto.

    3. The board takes standard PC133 NON-PARITY RAM. No way in Hell would I trust my data to something like that. Honestly, this is just plain stupid. The board is too expensive for the home market and no-one sane is going to put non-ECC memory in a server.

    [As a side point: Even using standard DIMMs, you could do some sort of block-ECC at the driver level (or in the controller chip) and use the fourth DIMM as a parity device to recover from on failures, like RAID-3. Alternately, you could treat each DIMM as a 48-bit device and use the remainder for ECC and Chipkill. There's nothing on Cenatek's site to suggest they do anything like this, though.]

    There's a few other things that annoy me: the lack of specifications (while they have a list of approved memory modules, they point-blank refuse to provide the required memory specs on their support forum). Also, the board appears to require four identical DIMMs, which is a royal pain in the bum. Expandability? What's that? Low entry cost? Don't got one of those either.

    So this board appears to be worthless for its target market and overpriced for anything else.

    One-word review: Sucks.
    Score: 3/10.

    Memory is absurdly cheap, and a properly thought out board (even one that implements the ECC in software) at the right price has a market waiting. I know a lot of people doing embedded Telco apps would love something like this. This card isn't it.

    The Platypus card is also over-priced, but it does support (indeed, requires) ECC, and also goes up to 8GB.

  47. *ONLY* a factor of TWO??? by fishbowl · · Score: 3, Interesting

    Performance gains of "almost a factor of two?"

    Does anyone else read that as an endorsement of the usefulness of buffering and other performance technologies applied to disk drives?

    I'd imagine that applications in ruggedized systems or devices that need to be exposed to significant acceleration or zero gravity will be more important than the speed increases, but, I'm quite surprised that a 15krpm SCSI drive comes this close to a RAM device.

    One other benchmark that would be useful, would be to compare the speed to the normal RAM in a given system. Is it a net gain to have your RAM on an expansion card? Or would a RAM drive on the regular memory space be better? Is this more or less expensive than system RAM?

    --
    -fb Everything not expressly forbidden is now mandatory.
  48. Not for home users... by Jah-Wren+Ryel · · Score: 4, Informative

    I don't know why a hobbyist website is reviewing this unit - the target market is not for hard-core gamerz or other home user types. Solid state disks are primarily used as database accelerators. Although the throughput of a solid state disk like this can be easily beat by a reasonably small raid, it takes a much larger raid to beat the io/s rate. If you have indices that don't fit in ram, you stick them on the solid-state disk and watch your database speed up by an order of magnitude.

    Alternatively, as at least one other poster has already mentioned - if you use a journalling filesystem like ext3 or rieserfs, then putting the journal on a seperate solid-state disk is a huge performance gain.

    --
    When information is power, privacy is freedom.
  49. Re:Platter-level RAID by orangesquid · · Score: 3, Interesting

    Actually, yes. It's some sort of funky medium-level format, IIRC (and it may even screw up your IDE drives permanently). But then again, the true low-level format includes all sorts of special blocks that store tracking information and bad sector tables. You wouldn't want your BIOS to screw with that. I don't trust my BIOS farther than I can throw it! (And, btw, a 120G drive actually has 130G-150G of disk space... you just can't use it ;)

    --
    --TheOrangeSquid Is it any wonder things seem so awry? We swim in a sea of confusion and don't have to think to survive
  50. Underachievers! by billcopc · · Score: 4, Insightful

    I don't get it.. let's assume, in the name of generosity, that U160 actually pushes 160mb constantly. Then the rocket drive pushes 320mb constantly. Now we've got PC3200 ddr ram that can theoretically push 3.2 gigs per second, while this rocket drive only does a tenth of that.

    What's the damn point ? It has to go through some sort of slow-ass bus anyways.. it's not like it has precisely timed local access to the northbridge, like traditional ram.

    It would be better for motherboard (and chipset) makers to accomodate buckets of ram sticks, so we can allocate a real RAM disk using 8 or 16 sticks of 512mb/1gb ddr.

    --
    -Billco, Fnarg.com