Performance vs. Transfer Size

All of our Iometer sequential tests happen at a queue depth of 1, which is indicative of a light desktop workload. It isn't too far fetched to see much higher queue depths on the desktop. The performance of these SSDs also greatly varies based on the size of the transfer. For this next test we turn to ATTO and run a sequential write over a 2GB span of LBAs at a queue depth of 4 and varying the size of the transfers.

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Read performance is now more consistent and better, especially at smaller transfer sizes. There is still an odd drop in performance at transfer size of 512KB but overall the performance scales better with the new firmwares as we increase the transfer size. Compared to other drives, Vertex 4 can't deliver all that great read performance between transfer sizes of 2KB and 64KB, though. 

Write performance at all capacities and transfer sizes is great. Only Intel's 240GB SSD 520 is faster, but this is expected since it uses a SandForce controller and ATTO tests with highly compressible data.

AS-SSD Incompressible Sequential Performance AnandTech Storage Bench 2011
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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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