Random Read/Write Speed

The four corners of SSD performance are as follows: random read, random write, sequential read and sequential write speed. Random accesses are generally small in size, while sequential accesses tend to be larger and thus we have the four Iometer tests we use in all of our reviews.

Our first test writes 4KB in a completely random pattern over an 8GB space of the drive to simulate the sort of random access that you'd see on an OS drive (even this is more stressful than a normal desktop user would see). I perform three concurrent IOs and run the test for 3 minutes. The results reported are in average MB/s over the entire time. We use both standard pseudo randomly generated data for each write as well as fully random data to show you both the maximum and minimum performance offered by SandForce based drives in these tests. The average performance of SF drives will likely be somewhere in between the two values for each drive you see in the graphs. For an understanding of why this matters, read our original SandForce article.

Iometer - 4KB Random Write, 8GB LBA Space, QD=3

It's a bit unfortunate for Intel that we happen to start our performance analysis with a 4KB random write test in Iometer. The 510's random write performance is only marginally better than the X25-M G2 at 49.7MB/s. The RealSSD C300 is faster, not to mention the SF-1200 based Corsair Force F120 and the SF-2200 based OCZ Vertex 3.

Although not depicted here, max write latency is significantly reduced compared to the X25-M G2. While the G2 would occasionally hit a ~900ms write operation, the 510 keeps the worst case latency to below 400ms. The Vertex 3 by comparison has a max write latency of anywhere from 60ms - 350ms depending on the type of data being written.

Many of you have asked for random write performance at higher queue depths. What I have below is our 4KB random write test performed at a queue depth of 32 instead of 3. While the vast majority of desktop usage models experience queue depths of 0 - 5, higher depths are possible in heavy I/O (and multi-user) workloads:

Iometer - 4KB Random Write, 8GB LBA Space, QD=32

While the X25-M G2 scaled with queue depth in our random write test, the 510 does not. It looks like 50MB/s is the absolute highest performance we'll see for constrained 4KB random writes. Note that these numbers are for 4KB aligned transfers, performance actually drops down to ~40MB/s if you perform sector aligned transfers (e.g. performance under Windows XP).

Iometer - 4KB Random Read, QD=3

Random read performance is just as disappointing. The X25-M G2 took random read performance seriously but the 510 is less than 20% faster than the Indilinx based Corsair Nova. When I said the Intel SSD 510's random performance is decidedly last-generation, I meant it.

A Word on Reliability & The Test Sequential Read/Write Speed
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  • deadsmeat - Wednesday, March 02, 2011 - link

    I am not sure if I missed it, but will you do a price/performance for SSDs? For example, and Intel or Corsair SSD migth be the fastest, but if it has a good price/performance vs the fastest SSD then it's something that consumers might consider when getting an SSD.

    I don't have a clear "performance" since you have run many benchmark in there, but something like a "real world load" would be good to see. I may not want the fastest SSD, but I will be looking for something that has good over-all balance in performance, and not so heavy on the pocket...
    Reply
  • deadsmeat - Wednesday, March 02, 2011 - link

    Woops, I missed "not" i.e.

    Intel or Corsair SSD might NOT be the fastest, but if it has a good price/performance vs the fastest SSD then it's something that consumers might consider when getting an SSD.
    Reply
  • dagamer34 - Wednesday, March 02, 2011 - link

    I thought that's what the light benchmark was, more "normal" tasks that aren't super-abusive with the SSD. Reply
  • vol7ron - Wednesday, March 02, 2011 - link

    Yes, light being "AnandTech Storage Bench 2011 - Light Workload".

    Either Light or Heavy depending on your use seems to be a combination of both random and sequential performance.

    As stated in the article:
    "I'll be sharing the full details of the benchmark in some upcoming SSD articles but here are some details:

    1) The MOASB, officially called AnandTech Storage Bench 2011 - Heavy Workload, mainly focuses on the times when your I/O activity is the highest. There is a lot of downloading and application installing that happens during the course of this test. My thinking was that it's during application installs, file copies, downloading and multitasking with all of this that you can really notice performance differences between drives.

    2) I tried to cover as many bases as possible with the software I incorporated into this test. There's a lot of photo editing in Photoshop, HTML editing in Dreamweaver, web browsing, game playing/level loading (Starcraft II & WoW are both a part of the test) as well as general use stuff (application installing, virus scanning). I included a large amount of email downloading, document creation and editing as well. To top it all off I even use Visual Studio 2008 to build Chromium during the test."
    Reply
  • therealnickdanger - Wednesday, March 02, 2011 - link

    What price would you use? MSRP? Newegg after MIR? Just pick a usage scenario that fits your usage and divide the score by the dollar amount of your favorite e-tailer... Pretty simple. Reply
  • vol7ron - Wednesday, March 02, 2011 - link

    Why not have both? AT has used a price grabber in the past.

    Actually, where did that go? It started to break down on the old site, but I'd like to see AT put that part shopper back up.
    Reply
  • MrDiSante - Wednesday, March 02, 2011 - link

    Realistically speaking, if you're buying computer components/peripherals, the function
    Retailer GetLowestPrice(Component component)
    {
    return Newegg;
    }
    would probably be better than the average price comparison site.
    Reply
  • marraco - Wednesday, March 02, 2011 - link

    To be useful, the comparison needs to consider RAID 0 setups. Reply
  • dagamer34 - Wednesday, March 02, 2011 - link

    It seems like the one true major difference between the Intel SSD 510 and the OCZ Vertex 3 is that one is available now while the other is only talked about in reviews. First to market is always a benefit for a manufacturer that has a decently performing product, though Newegg's markup makes early adopter's pay dearly for it.

    Of course, this leads to the important question of "when will the Vertex 3 series reach general availability?" I recently purchased a 120GB OCZ Vertex 2 for a new 2011 17" MacBook Pro and the performance is stunning compared to the stock HDD (it's my first SSD). I'm wondering if I should return the drive and just wait for the Vertex 3 because once you've gone SSD, it is so hard to go back!

    Thanks for the review Anand!
    Reply
  • dagamer34 - Wednesday, March 02, 2011 - link

    Oh, another thing. Are we going to get an SSD State of the Union for 2011? I'm guessing you're waiting to finish the reviews of most of the SSDs that are coming out this year first... Yeah, I just answered my own question, I think. :) Reply

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