Performance vs. Transfer Size

ATTO does a good job of showing us how sequential performance varies with transfer size. Most controllers optimize for commonly seen transfer sizes and neglect the rest. The optimization around 4KB, 8KB and 128KB transfers makes sense given that's what most workloads are bound by, but it's always important to understand how a drive performs across the entire gamut.

Vector clearly attempts to shift the Vertex 4's performance curve up and towards that of Samsung's SSD 840 Pro. There's a fairly repeatable anomaly at 32KB and 64KB where performance drops down to Vertex 4 levels, but generally speaking there's a tangible improvement across the board. My guess is whatever is happening at 32KB and 64KB is a bug though. Barefoot 3 has no issues parallelizing workloads that are smaller.

I would still like to see improved 512B transfer performance, but other than Samsung it doesn't look like anyone is really focusing on smaller-than-4KB performance anymore. Even Intel has pretty much abandoned focusing on it with its S3700 controller. I may just have to give up caring about it. Smaller than 4KB performance really doesn't impact most client workloads, it's really the weird corner cases where it would matter. Just don't go off and use any of these drives under Windows XP and you'll be fine.

When it comes to write performance, OCZ has delivered a solution that seems to be a hair quicker than the 840 Pro in many of the smaller transfer sizes, and a lot faster once we get to the larger block sizes. Performance vs. the Vertex 4 is clearly improved, and there's only a mild indication of whatever weird issue was happening in the read test.

Sequential IO Performance Performance Consistency
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  • Death666Angel - Friday, November 30, 2012 - link

    In one of the podcasts (E10?) Anand talks about how SF controllers have less issues with these IO latency worst case scenarios. So it's not necessarily an Intel feature, but a SF feature and the graph might look the same with a Vertex 3 etc.
    Also, it may behave differently if it were filled with different sequential data at the start of the test and if the test were to run longer. I wouldn't draw such a positive conclusion from the test Anand has done there. :)
  • jonjonjonj - Thursday, November 29, 2012 - link

    did they have to name their 2 drives Vector and Vertex? they couldnt have picked 2 names that looked more alike if they tried. i have to image this was done on purpose for some reason that i can think of. now that ocz has its own controller are they retiring the vertex or will they just use barefoot controllers in vertex ssd's going forward?
  • deltatux - Sunday, December 2, 2012 - link

    While it is great that the OCZ Vector is able to compete with the Samsung SSDs in terms of performance, but OCZ's past reliability records have been iffy at most, they fail prematurely and RMA rates have been quite high. I've known countless people suffering issues with OCZ drives.

    I'll wait for a bit before recommending OCZ drives to anyone again due to reliability issues if the OCZ Vector can meet the reliability of Corsair, Intel or Samsung drives. Until then, I'll keep recommending Samsung drives as they exceed in performance and reliability than most manufacturers.
  • rob.laur - Sunday, December 2, 2012 - link

    If you check the review of the Vector on the hardwarecanucks website, page 11 you will see the Vector AND Vertex crush every other drive listed when filled with over 50% capacity. This is probably the most important bench to judge SSD performance by.

    "While the Vector 256GB may not have topped our charts when empty, it actually blasted ahead of every other drive available when there was actual data housed on it. To us, that’s even more important than initial performance since no one keeps their brand new drive completely empty. "
  • jwilliams4200 - Sunday, December 2, 2012 - link

    If you are talking about this:

    http://www.hardwarecanucks.com/forum/hardware-canu...

    you will note that the Samsung 840 Pro is conspicuously absent from the list, so we do not know how the Vector fares against its most difficult competitor.
  • rob.laur - Sunday, December 2, 2012 - link

    you are right and I wish they did include the 840 Pro but they didn't. Point is compared to all those other SSDs/Controllers, the BF3 clearly outperforms everything in the real world with actual data on the drive. The 840 Pro uses faster nand than the Vector yet both drives are pretty much equal. The toshiba toggle version of Vector cant come soon enough!
  • jwilliams4200 - Monday, December 3, 2012 - link

    The Samsung 840 Pro is significantly faster (about 33%) than the Vector for 4KiB QD1 random reads. This is an important metric, since small random reads are the slowest operation on a drive, and if you are going to take just one figure of merit for an SSD, that is a good one.
  • rob.laur - Monday, December 3, 2012 - link

    well according to most sites, the Vector beats it on writes and in mixed read/write environments especially with heavy use. Not to mention the 840 takes a long time to gets its performance back after getting hammered hard whereas the Vector recovers very quickly.
  • jwilliams4200 - Monday, December 3, 2012 - link

    First of all, the type of heavy writes I believe you are referring to are a very uncommon workload for most home users, even enthusiasts. Reads are much more common.

    Second, I have seen only one credible study of Vector use with heavy writes, and the Samsung 840 Pro does a better than the Vector with steady-state, heavy writes:

    http://www.anandtech.com/show/6363/ocz-vector-revi...

    I have seen nothing to suggest the Vector recovers more quickly. If anything, there is circumstantial evidence that the Vector has delayed recovery after heavy writes (assuming the Vector is similar to the Vertex 4) due to the Vector's quirky "storage mode" type behavior:

    http://www.tomshardware.com/reviews/vertex-4-firmw...
  • jwilliams4200 - Monday, December 3, 2012 - link

    My first link was meant to go to storagereview:

    http://www.storagereview.com/ocz_vector_ssd_review

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