Are SSD Accelerators Any Good?
MrSeb writes "When solid-state drives first broke into the consumer market, there were those who predicted the new storage format would supplant hard drives in a matter of years thanks to radically improved performance. In reality, the shift from hard drives (HDDs) to SSDs has thus far been confined to the upper end of the PC market. For cost-conscious buyers and OEMs, the higher performance they offer is still too expensive and the total capacity is insufficient. SSD cache drives have emerged as a means of addressing this situation. They are small, typically containing between 20-60GB of NAND flash and are paired with a standard hard drive. Once installed, drivers monitor which applications and files are accessed most often, then cache those files on the SSD. It can take the software 1-2 runs to start caching data, but once this process is complete, future access and boot times are significantly enhanced. This article compares the effect of SSD cache solutions — Intel Smart Response Technology, and Nvelo Dataplex — on the performance of a VelociRaptor, and a slow WD Caviar drive. The results are surprisingly positive."
For Linux users: http://bcache.evilpiepirate.org/
Lets you use any SSD as a cache in front of another filesystem.
Hybrid drives or mixed mode setups kinda suck ass now that actual ss drives are getting to a reasonable price/size.
SSD for os/programs.
Giant TB+ drive for storage and media files.
While the apps run on the hard drive due to the low capacity. To me it is not worth it to watch your os boot faster. Windows 7 loads in about 35 seconds on my computer which is only a Phenom II and not a fancy i7 or anything.
What also is not addressed in the article is the reliability of the SSDs. Flash ram is not a permanent solution and will die due to the limited number of writes. If you use mysql or MS access or run low on space and use XP that thing will be dead in a matter of months. It can only handle so much paging and writes before it dies. Tricks in the firmware move the write bits to random places in memory to prevent this but as it fills up the paging needs to keep to keep hiting the same memory addresses.
I am going to wait for a few years until they use a different memory technology that can have unlimited writes as well as larger capacities. It is not worth it to me yet.
http://saveie6.com/
240GB SSDs are bouncing around 200. 2 bills for the boot SSD and your old drive gets the data partition and you are beating these hybrids on performance AND price.
They did not include a true hybrid like the Seagate Momentus. No stupid driver tricks needed to make it work, it would have been really great to see how it compared to what was reviewed.
It seems that SSD accelerators can be hit/miss. If you take a look at http://www.theregister.co.uk/2012/07/12/velobit_demartek/ for example, some of these products don't seem to do anything - while some seem to actually work.
Like any young industry, it'll probably a while to shake out field until only a few decent contenders remain.
Nemilar http://www.techthrob.com - Visit Me!
It would be surprising if it weren't the case. We've been doing the same thing with memory for years. Our CPUs need memory that can perform in the realm of 100GB/sec or more with extremely low latency, but we can't deliver that with DRAM. So we cache. When you have multiple levels of proper caching you can get like 95%+ of the theoretical performance you'd get having all the RAM be the faster cache, but at a fraction of the price.
This is just that taken to HDDs. Doesn't scale quite as well but similar idea. Have some high speed SSD for cache and slower HDD for storage and you can get some pretty good performance.
I love Seagate's little H-HDDs for laptops. I have an SSD in my laptop, but only 256GB. Fine for apps, but I can't hold all my data on there (music, virtual instruments, etc). They are just too pricey to get all the storage I'd need. So I also have an H-HDD (laptop has two drive bays). It's performance is very good, quite above what you'd expect for a laptop drive, but was only $150 for 750GB instead of $900 for 600GB (the closest I can find in SSDs).
SSD's were recently @ $1/Gig. That's when I upgraded everything.
I've seen them as low as 55-65c a gig now. Yeah... gotta love how
tech drops in price RIGHT AFTER you decide to adopt.
Buy a WHOLE SSD drive. Put all the programs you use daily on it.
120G ~ $70
That is all.
FWIW, except for bulk storage, I will NEVER buy a spinning HD again.
I experienced a RIDICULOUS speed up, going from a 7200rpm drive.
-AI
For me, it is far better to grasp the Universe as it really is than to persist in delusion
> In reality, the shift from hard drives (HDDs) to SSDs has thus far been confined to the upper end of the PC market.
Not entirely. I have the cheapest netbook I could find, and I replaced its hard drive with a cheap low-capacity SSD. I don't keep much big stuff on it so the capacity isn't a problem. In terms of performance and power usage and not having to worry about my data when I drop my computer, it's been entirely worth it.
This is exactly what has been going on in the enterprise storage space for a while. I only know much about two vendors, but they both have a solution like this. High end IBM storage has EasyTier, which while originally for the mix of FCAL/SAS to SATA, it works with SSD too, and in the latest revs all 3 tiers at the same time. NetApp used to have a PAM card which is now called... FlashCache? FlexCache? F-Something-Cache anyway, which is essentially an SSD drive on a PCI card.
Good to see the high end tech being applied to consumer level workloads.
----- - The beatings will continue until morale improves
The article doesnt mention any other software(mostly OS) requirements for the accelerators, which is a pretty big deal. Basically there are 2 ways to cache:
1. On the file level, which isnt very resource intensive(there aren't nearly as many files as blocks on a disk), but requires that the accelerator be able to read file system metadata(and of course be able to intercept OS calls) which severely restricts what kind of file system, and really even operating systems, you can use with the accelerator
or
2. Block-level caching. Much more generic, can really be used with any file system as the blocks, not any file system metadata, are the only thing that is used. However managing all that block information comes at a cost, either in main memory or more expensive hardware. For instance Flashcache requires about 500 megs of memory to manage a 300GB disk. Depending on your usage this may be acceptable(though is memory really that much cheaper than ssds nowadays?) but for most it isnt.
From the article I can assume that they only tested Windows, and that really limits its usefulness.
Monstar L
In reality, the shift from hard drives (HDDs) to SSDs has thus far been confined to the upper end of the PC market.
In reality, 100% of the smartphones, tablets, many/all? of the ultrabooks, and many notebooks now ship with SSDs. In a short time, virtually all laptops will ship with SSDs.
Disks will go the way of tapes. You'll be able to get them, but the practical uses will be few.
In reality, I imagine that more computers (yeah, I count smart phones and tablets) are now sold with SSDs than disks.
As to your actual question about accelerators - I have no idea. I went solid state a couple of years ago and won't be going back.
With pretty much any modern drive (whether platter based or solid state) if you are paranoid about data security you have two options, either encrypt everything that may ever hit the drive or physically destroy the drive when you are done with it. Both platter based and soild state drives have remapping systems in place (though soild state drives to a lot more remapping) such that it is pretty much impossible to gaurantee an external overrwrite will hit anything. Both have built-in "secure erase" commands but noone except the manufacturers really knows how secure they are.
note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register
Booting? Who boots their computer? I'm like a lot and on a UPS at home, and boot? I might boot once a month, if that. If I need to boot, I'll grab something from the fridge, take a bathroom break for the 1-2 minutes it takes to reboot. The minor boost I would get from a SSD pales in comparison to the SPACE I would benefit from...for now. If/when the price gets down to the mechanical drive pricing per gig, I'll give it another go, but for now, I'll take the space over speed.
SSD prices have fallen quickly, while hard drives have gone up. If you don't need large amounts of storage it's better to just go SSD. But what if large amounts of storage are needed?
I would recommend buying an SSD, putting the OS and all applications on it, and then using a magnetic drive as the "users" volume. Any sanely laid out OS makes this very easy. The OS and Apps will load quickly, the large items (like video) will be stored on the cheaper, larger disk storage. No "hybrid" algorithm to worry about working. Two separate parts that can be upgraded independently. No OS support required. Perhaps some acceleration of some small data files will be missed, but the large ones would have never fit in the accelerated flash anyway.
I do think that file systems need to evolve in a new direction. ZFS is a preview in the right direction, but it would be nice to have a file system where you could add ram disk, or flash disk and tell it to be used as a "cache" for underlying disk, write through or write back. Easy to do in software. Plus better backup and replication support. I'd really like to configure my laptop with a 2TB spining disk, 256G super-fast SSD, and give 1G of RAM to the file system. Tell the file system to write everything through to magnetic, cache frequently used in SSD and RAM. When I'm on the hope network replicate the spinning disk to my NAS bit for bit. Perform incremental backups to my cloud backup service when connected to a fast enough network using compressed incremental to save space. Give me all that with ZFS's other features and it would be sysadmin filesystem nirvana...
i dont know about windows, but, wouldn't a more elegant way to accomplish this be paging? having a very large swap on the SSD portion and a very high swappiness value would sort of do what this intends to do, without such an end-run around the entire cache architecture of the OS
While the performance may be nice I still have a lot of concerns about reliability of SSDs.
I bought a Crucial M4 256GB SSD about 9 months ago and it started to fail a week or two ago.
So far Crucial won't RMA it and just keeps asking meaningless questions via email.
What kind of reliability are people seeing in SSD and hybrid drives? What happens when the NAND flash dies on a hybrid drive?
I've got hard drives that have been running non-stop for years without a problem. From my experience so far SSDs just don't match up in that regard.
Here is a good idea for linux
/, and then mount your magnetic disk for /home.
plug your SSD into SATA slot one, a large magnetic disk into slot two.
install the bootloader and OS onto the SSD, and use it for
problem solved. Of course this works for any pair of "large but slow" and "small but fast" disks.
TFA at extremetech isn't that feature rich, nor embarking on a brand new frontier that none of us had ever been
TFA could have been made into ONE PAGE, but no, extremetech ain't gonna let us, the readers, enjoy it in one shot - we had to click through all the 5 pages
Please, Slashdot !
Next time you give us a link to a single TFA with multiple pages, please indicate it right upfront
Thank you !
Muchas Gracias, Señor Edward Snowden !
Be very careful - Nvelo says you cannot install any windows update or image the drive. http://www.ocztechnologyforum.com/forum/showthread.php?99185-OCZ-synapse-cache-128Mb-Nightmare-to-get-it-to-work-I-beg-for-help
ZFS already supports flash devices for caches. For read caching (L2 ARC), you can create striped cache volumes. You get better speed that way, and if one of the devices fails, ZFS knows it and just goes straight to the main storage volume (the one being cached). Meanwhile, the other drive continues. For write caching (ZIL), since the data is "worth" more, you can create a mirror of flash devices. The benefit of the ZIL is realized even if the cache is small, but unfortunately SSD write speed can be worse than writing to regular drives (see below about SLC drives).
The best theoretical configuration would be, at a minimum:
- two small (and fast) SLC devices, mirrored and used for write caching
- two large(r) MLC devices, striped and used for read caching
- a redundant array of inexpensive drives (someone should come up with a catchy term for that), of huge capacity but otherwise slow (5400 rpm)
In place of the SLC drives, there are even more expensive (but higher performing) options, such as a bank of volatile RAM with a battery backup, and an SSD that the RAM contents get copied to in case of a power loss. These exist, and really work. The theory of a pyramid of caching; with "slower and cheaper" at the base and "faster and pricier" towards the top really has been shown to work.
ZFS can do all of this right now, and continuing a little off topic... can also do compressed incremental volume snapshots sent into the cloud :)
Yeah, I do a lot of work with ZFS. All of this stuff really works.
SSD aren't just for high end systems. Out of my 300 or so past customers, approx 3 filled their hard drives to over 60GB total. I built several Kingston HyperX 90Gb and OCZ Agility 4 128GB drives without problems and they were all $500-600 final cost. I use an H77MA-G43 from MSI + 4GB Gskill 1333-CL7 memory and i3-2100 or 4GB 1333-CL9 and a Pentium B940-960. Put it in a decent $30-40 case, use an Antec VP450 or Basiq or other respectable but medium end PSU, and wait for a sale on Win7 64-bit OEM copies for $80 instead of $100 and you've got yourself an unbeatable, 7 year anticipated lifetime machine. Here's the kicker.
I have an i5 (sandy) ridiculous gaming computer with a GTS450, 8GB of CL7 RAM, P67 chipset, and a pretty fast 7200 RPM 1TB Seagate main drive. It's custom built and would be around $1000 retail at my shop (at the time at least). It takes over a minute to log in and it takes forever to load games.
I also built a system I'm selling for $520 with a Pentium B950, 4GB of pretty standard RAM, and a Maplecrest 60GB SSD. It logs into Windows in 4 seconds. The glowing balls don't even touch while loading the Windows 7 logo.
SSDs are not for high end systems only! They're specifically exactly the opposite. They're the best way to make a really cheap budget PC seem extremely fast.
http://www.asus.com/Motherboards/Intel_Socket_2011/P9X79_PRO/
This is NOT taxing the CPU, this is all hardware controller chip.
I haven't tried it out yet, but you pair any old SSD you want with any old HD you want, and voila.
The obvious selling point is that it is so easy.
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
Hybrid drives have been on the market for years. It seems to me your risk exposure is only increased by combining the two. You now have to worry about the perils of spinning platters, oxide eating flash write operations and new management technology gluing the systems together not widely deployed.
The last I checked about a year ago there were overwhelming negative comments related to reliability of hybrid drives. Even assuming all the bugs have since been worked out seems like such a fleeting and pointless stop-gap measure as to not be worthwhile.
I have enough memory that most applications load instantly from the operating system cache. 32GB of ddr is readily available for less than $200 ... nothing involving a SATA bus can be faster than the operating systems main memory disk cache.
Hopefully memristers or other technologies will pan out soon and we can be done with slow, power hungry access and inherently unreliable storage mediums once and for all.
You'll still have slowdowns when you boot and the first time you access data.
No matter how much memory you have, it's going to be slow the first time you access something after booting up.
Can anyone point me to a good SSD-caching hard disk for a laptop, with a total SSD+HDD size of 500 Gb or more?
I want the benefit of rapid OS and application start-up, but also need the large disk space, so a simple SSD is still too expensive at these sizes. Other solutions for Laptops don't quite cut it... I'd rather not lug around an external HDD everywhere, and Laptops generally only have one drive bay, so I can't have one small SSD + one large HDD... Microsoft ReadyBoost is an alternative but requires a USB key or SD Card and probably isn't as effective as a firmware-based SSD-caching HDD.
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Seagate Momentus XT are hybrid drives in both laptop and desktop form factors. For cases where you can only have one drive, in a notebook, you have no choice.
I have a 750 Gb Momentus XT in my laptop and the performance increase is noticable. And the drive only costs 30$ more then the non-bybrid one. Definitely worth the money.
The dangers of excessive individualism are nothing compared to the oppressiveness of excessive collectivism
When I got my new Z77 board last week, I managed to slice my 120gb SSD into two parts. 18gb for Intel's cache system, and rest for "Data" - aka Windows install.
I configured the SSD to cache my 2tb spinney a bit, and it generally worked as expected. Performance ranged from clean SSD speed some places, to in worst case old HDD speed.
In other words, worst-case scenario was same as not having cache, and best-case scenario made it look like a 2TB SSD at no extra cost :)
I've currently disabled it, since currently I'm re-installing my steam games (over 300 in total..), but will re-enable it when the data is a bit more static again.
So far I consider the experiment a huge success, even though it complicated the install somewhat (SSD cache can only be configured from Windows, and only if the SSD is not running the OS).
It's The Golden Rule: "He who has the gold makes the rules."
As others have commented, Linux has bcache and flashcache. If don't need everything to be GPL, it also has ZFS, which I use. The RAM caching of ZFS is top notch, but the SSD caching is extremely simplistic. I find that it performs really well, though, and using RAID and data checksums gives peace of mind. The cache is flushed on boot, so it's not good for things like laptops. There is also a separate system for write buffering, in addition to the read cache.
The cost benefit of SSD's barely makes sense - the makers got greedy and decided to tack absurd price premiums on their gear far in excess of their benefit. And they've stayed there.
What Joe Consumer needs is an odometer equivalent for an SSD; something that can explicitly warn us when we're reaching the MWI cliff so we can plan for an upgrade (including nuking the old SSD) before we possibly lose even one bit. Without that, it's just murder in the dark.
If it requires O/S level drivers to implement the cache, then it's NFG.
SSD caching has promise, but it needs to be done in hardware, and be completely transparent to the O/S on top of it.
it's a marvell controller
it has different features (SSD size doesn't matter, ease of setup)
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
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I think we can end ANY additional article about the merits of storage technologies using the following unified equation
future tech > SSD > SSD Hybrids > HDD > optical disks > floppy drives > tape drives > punch cards > wall paintings > iCloud
I haven't thought of anything clever to put here, but then again most of you haven't either.
If we're talking about SSDs in the last 14 month period, give or take a few months, keep in mind there was a huge batch of sandforce-based SSDs that, for a while, had very, VERY buggy firmwares that caused everything from constant crashes, blue screens, freezing, bad writes that corrupted everything whenever you patched the system or installed new software.... The firmware updates eventually came out that fixed the issue completely, but that took a while, and I expect most people who bought one of these (they were the cheapest "fast" SSDs for quite some time...don't know about time) to be having nothing but trouble, and resellers would replace them under warranty (which was pointless: the new one would also have the bad firmware).
We went through 3 of these ourselves until we realized it was a firmware issue, and it took 2-3 firmware updates each stating they would "FINALLY" fix it before they actually did.
Not saying that covers all the cases, but considering how common those SSDs were last year, it probably is the cause of quite a few.
Absolute minimum latency for a fetch is 16ms on USB port
Where are you getting this number? I develop USB devices (Cypress FX2 Hi-Speed and a PIC for Full-Speed), and a USB Hi-Speed microframe is transmitted every 125 microseconds. When I initiate transfers, they almost always go out during the next microframe. I can and have sent two packets back and forth in a single millisecond, and that's without sending multiple packets per microframe (I believe I've seen up to 17 bulk packet transfers in one microframe before in a Cypress app note comparing bulk to isochronous).
The only USB devices I'm aware of with such poor latency are keyboards and mice, because they're generally low-speed devices.
Is this 16ms fetch latency some artifact of the OS? Because it's certainly not a limitation of the hardware and software, as I can personally attest to.
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I haven't bought a PC game that requires a disc in the drive to play for years. They all have a full install and some form of DRM (often Steam) now.
I probably have about sixty games installed on my PC, and I think one of them needs a disc in the drive to work. And that's Dune 2000, which is a) old as hell, and b) plays the video files off the CD, doesn't install them.
I haven't reinstalled Windows 'to regain lost performance' in years, either. I've never had a problem with it slowing down.
Of course, I only install the things I _need_ on it, to do the things I want to do. Games? Yes, to play them. Video transcoding software? Yes, because I need to work with files. Massive 'Community Codec Packs'? No, because they screw things up.
I just install everything to my hard drive and let a caching SSD figure out which files need speeding up at the moment. It's just easier.
Back when I was really much of a gamer, because needing to have a cd (for that's what games came on at that time) in my drive to play a game pissed me off to no end (especially because it usually meant it was swapping things off the cd periodically, too, which was slow), I just made iso rips of my games, then mounted them to a virtual drive when I wanted to play one. Granted, I put all those isos onto an external, and only copied ones I was actively playing onto my primary drive, but still.
I have more than a hundred gigs just of music, and it's quite nice having all of -that- on my primary drive. If my laptop could've supported a SSD, a larger HDD and a dvd-r drive, I probably would've gotten all three. Sadly, it only had space for two, so I chose the 500 gig hdd and a dvd-r, and I'm not sad about that decision.