Performance: Welcome to the 500 Club

Let’s talk peak performance specs. I must preface this with a warning, all of the numbers you’re about to see are SandForce’s estimates and projections for how the SF-2000 series will perform. Next week you’ll see some basic functionality and performance testing but as far as I know, these numbers haven’t been reached yet. SandForce is confident that it will hit them once drives start shipping, but until then take what you are about to see with a grain of salt.

Random read and write performance goes up significantly over the SF-1200/1500. We are at 40K IOPS today, and SandForce is promising 60K IOPS with the SF-2000. Note that this is not only higher than anything shipping today, it’s even higher than what we recently found out about Intel’s 3rd generation X25-M/X25-E SSDs.

Now the shocker. Thanks to 6Gbps and ONFI 2/Toggle support, the SF-2000 will support up to 500MB/s sequential read and write speeds. On an 8 channel device that’s actually only 62.5MB/s per channel but the combined bandwidth is just ridiculous for a single drive. At full speed you could copy 1GB of data from a SF-2000 drive to another SF-2000 drive in 2 seconds. If SandForce can actually deliver this sort of performance I will be blown away.

Let’s talk about reality for a second. SandForce quotes standard iometer numbers, which are usually quite optimistic for SandForce's controllers. I’d expect real world performance to be a bit below these figures but not by a lot for many workloads.

In the SF-1200/1500 series, SandForce used enterprise features to differentiate the two controllers. You got some improved reliability and a giant capacitor with the SF-1500 designs, but you didn’t really get any added performance. With the SF-2000 series, we will see more differentiation between the enterprise and consumer parts. SandForce indicated that the consumer version of the SF-2000 would have a different level of performance. I get the impression that the specifics of the consumer drive haven’t been determined yet. I’ve already started campaigning to see a full spec version in the consumer market but it’s still far too early to tell what will be shipped. If the 3rd generation X25-M is really only capable of 270MB/s reads and 170MB/s writes, I’m not sure if there will be the motivation to deliver a 500/500MBps part into the enthusiast market.

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  • jwilliams4200 - Thursday, October 7, 2010 - link

    It is the Sandforce marketing department that is impressive. They have a lot of people drinking their Kool-aid. But Sandforce's actual technology does not live up to their hype.
  • therealnickdanger - Thursday, October 7, 2010 - link

    It doesn't?

    http://www.anandtech.com/Bench/SSD
  • jwilliams4200 - Thursday, October 7, 2010 - link

    Note that the Sandforce drives got beat by the C300 and the X25-E on the benchmark you cited. Neither of those SSDs claims a write speed as high as 275 MB/s as Sandforce does.

    Also check out these benchmarks of copying real data files:

    http://www.behardware.com/articles/794-11/ssd-2010...

    The Sandforce drives do not even achieve 50% of their claimed write speed when faced with copying realistic data files. With real files, their write speeds are about 130 MB/s on a fresh SSD, and drop to about 83 MB/s on a well-used SSD.

    This from a company that claims 275 MB/s write speeds. Sandforce is good at hype, not so much at delivering what they claim.
  • jwilliams4200 - Thursday, October 7, 2010 - link

    Also check out these benchmarks of copying real data files:

    (couldn't include this in previous comment)

    bit.ly/96HJIL

    The Sandforce drives do not even achieve 50% of their claimed write speed when faced with copying realistic data files. With real files, their write speeds are about 130 MB/s on a fresh SSD, and drop to about 83 MB/s on a well-used SSD.
  • therealnickdanger - Friday, October 8, 2010 - link

    Seriously, how often do you spend the majority of your time copying that many files to other drives?

    Those examples are pretty selective and also, it's hardly fair to pit SLC against MLC. Special use scenarios are all fine and good, but for your typical user, the current SF MLC drives beat Intel MLC in typical multi-tasking real-world scenarios (AT's benchmark, Vantage).

    According to AT's reviews of SF-based drives, they all bounce back original speeds after TRIM... with "real" files. Intel degrades over time as well and then is restored after TRIM. It's the nature of the beast.

    The evidence points strongly to SF beating out Intel overall by a substantial margin in real-world and synthetic tests, with Intel only winning in a handful of non-typical scenarios. I think you're just seeing what you want to see.
  • jwilliams4200 - Friday, October 8, 2010 - link

    Copying files is a basic benchmark which gives an indication of how all other reads and writes will go. If a drive performs at less than half its claimed specification when copying files, you can be sure that it will perform similarly poorly on other tests.

    Yes, Anand's tests missed the Sandforce problem of performance degradation that cannot be recovered through TRIM, I'm not sure what your point is. Surely no one thinks Anand is perfect. The problem is real, and has been observed by bit-tech and by computerbase. I have also spoken with several people who have seen the problem themselves.

    And the evidence is that Intel matches or beats Sandforce on most real world tests, when you are looking at a well-used drive. Sandforce's used performance degradation is really bad when you are writing data that its controller cannot compress.
  • 'nar - Sunday, October 10, 2010 - link

    Famously simple answer:

    "You're holding it wrong."

    Copying files is not necessarily representative of normal workloads, you need a course in deductive reasoning. You cannot assume that large, contiguous, compressed files copied one at a time are at all representative of small, uncompressed, random files accessed concurrently.
  • Breit - Saturday, October 9, 2010 - link

    This seems to be a bit unfair with SF. Since their Controllers (or lets say SSDs with their controllers) can achieve a fairly high IOps count, you should at least bench the aggregate bandwidth they achieve with multiple file transfers at once...

    If this is a realistic workload or not depends entirely on your needs of course, but you also should choose Hard Drives and especially SSDs depending on your application and what delivers the best performance for you. Maybe SF-SSDs aren't the best SSDs for your average workload if speedy large single-file data transfer is your main goal. :)
  • 'nar - Sunday, October 10, 2010 - link

    Anand has covered this already. Compression reduces write amplification, thus improves performance in most workloads, and extends Flash life by writing to NAND less.

    "SandForce’s controller gets around the inherent problems with writing to NAND by simply writing less" - from this article.

    Then here is the test with truly random data:
    http://www.anandtech.com/show/3681/oczs-vertex-2-s...

    No drive is perfect. Most large files, such as what you linked with 6.8 GB files, are compressed already. Highly compressed files like movies do not benefit from SF compression, but they also don't need to. How fast do you watch a movie? All of my movies are on hard drives.

    This is not Kool-Aid, this is a choice. Use what is most appropriate for your workloads. Don't trash-talk the drive or mislead others due to one type of synthetic benchmark, or one supposed "real world scenario" that really is not what most people would use them for anyway.

    Just accept that this drive has less performance with compressed, encrypted, or truly random files. I have, and I have moved on. I have purchased three sf drives while being fully aware of that fact, two OCZ LE's and a G.Skill Phoenix Pro. I do not use compressed data on them anyway, just windows and applications, all are compressible. Well, mostly compressible.
  • vol7ron - Thursday, October 7, 2010 - link

    I imagine the added compression generates more heat for these components.

    Do you think that it will deteriorate the drive quicker?

    I'm not up to speed on the cooling inside an SSD, but I'm curious what happens to performance when a few cells in the proc begin to go.

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