AS-SSD Incompressible Sequential Performance

The AS-SSD sequential benchmark uses incompressible data for all of its transfers. The result is a pretty big reduction in sequential write speed on SandForce based controllers, while other drives continue to work at roughly the same speed as with compressible data.

Incompressible Sequential Read Performance - AS-SSD

AS-SSD's sequential read performance has surprisingly gone downhill with the 1.4 firmware. The drops are not huge, only 17.1MB/s (~4%) for 256GB model and 31.5MB/s (~7%) for the 512GB one. While firmware 1.5 brings some improvement, it's not enough to take performance back to the level it originally was.

Incompressible Sequential Write Performance - AS-SSD

OCZ claimed increased sequential write speeds with both 1.4 and 1.5 firmwares. IO Meter didn't show any significant changes but AS-SSD is telling a different story. The 256GB model gets a substantial boost of over 100MB/s and the 1.5 firmware should give a small increase as well if the scores of 512GB model are anything to go by. Vertex 4 is definitely in its own class when it comes to high queue depth sequential write performance, although we'll find out how big of a deal this is in real world performance once we get to AnandTech Storage Benches. 

Random & Sequential Read/Write Speed Performance vs. Transfer Size
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  • ewood - Monday, August 6, 2012 - link

    You shouldn't feel cheated if you bought the drive thinking read performance was corrected. The increase in read performance does not go away when going from performance mode to storage mode; only write performance in affected. So if you chose to buy the drive when the read performance was corrected you should see those gains regardless of used capacity of the drive. And as a side benefit if less than 50% of the drive is used you also get increased write performance.
  • MadAd - Wednesday, August 8, 2012 - link

    the point of a test is to create an environment to repeat runs and compare the differences between them, the fact it wasnt X full or Y empty isnt an issue as long as all drives are treated the same way

    we arent concerned if the tests dont reflect what a users drive looks like, users vary, what concerns us is if the tests can be used as a comparison from one drive to another, and we see that they can.
  • althaz - Saturday, August 4, 2012 - link

    I only keep my 240Gb SSD half full. I have Windows, Office, my browser, Broodwar and Starcraft 2 on it and that is pretty much all.

    I would suggest that most people don't actually put that much stuff on their SSD, unless it is in a laptop.

    On a 128Gb drive, though you are more likely to have it at least 3/4 full.
  • doubledeej - Saturday, August 4, 2012 - link

    But most people aren't buying excess capacity they don't intend to use. If you're never going to use more than half of your drive, why waste the extra money (nearly double in many cases) on space that is just going to go to waste?

    Most people will buy a drive sized appropriately for their needs, and nothing more, when it comes to SSDs. Especially since the prices just keep dropping and performance keeps improving. Buy what you need now, and upgrade later if you need to.
  • mattlach - Monday, August 6, 2012 - link

    Exactly.

    I use an SSD for my operating system, programs, games and a few files I am currently working on. Everything else gets stored on my NAS.

    I opted for a 240GB SSD this time around as my old 120GB Agility was a little tight for this purpose, and I was running out of space.

    With my usage model, I will likely not come even close to filling the 256GB drive, but I'll likely go just over the 50% mark, which is why I am concerned.
  • MrSpadge - Sunday, August 5, 2012 - link

    Sure, SSDs are faster when not fully loaded. But paying 2x as much for double capacity, just for this little performance bonus? Not a good value proposition.
  • sequoia464 - Saturday, August 4, 2012 - link

    Any chance of filling the 128 model up over 50% and running the tests over again?

    Most of my drives are more than 50%, it would be nice to know what the final usage speeds will actally be for these drives once they get some of their capacity filled.
  • mattlach - Sunday, August 5, 2012 - link

    I support this fully.

    It would be good to know what exactly we can expect once the drive goes past the 50% mark.

    Also, it has been stated that this is a once time calculation and reorganization of data. Does this mean that if you do a fresh install, or otherwise clear up space, you can never get the performance mode back?

    We need answers to all these questions.
  • Bull Dog - Saturday, August 4, 2012 - link

    Did power consumption change at all? I'm always interested in this metric due to the impact it can play on battery life.
  • lbeyak - Saturday, August 4, 2012 - link

    Yes, I thought in the previous Vertex 4 articles, it was mentioned that the high idle power usage would be addressed with this firmware update???

    Would be great to know.

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