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.

Desktop Iometer - 4KB Random Read (4K Aligned)

Desktop Iometer - 4KB Random Write (4K Aligned) - 8GB LBA Space

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:

Desktop Iometer - 4KB Random Write (8GB LBA Space QD=32)

Sequential Read/Write Speed

To measure sequential performance I ran a 1 minute long 128KB sequential test over the entire span of the drive at a queue depth of 1. The results reported are in average MB/s over the entire test length.

Desktop Iometer - 128KB Sequential Read (4K Aligned)

Desktop Iometer - 128KB Sequential Write (4K Aligned)

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.

Incompressible Sequential Read Performance - AS-SSD

Incompressible Sequential Write Performance - AS-SSD

The Review AnandTech Storage Bench 2011
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  • Coup27 - Tuesday, April 10, 2012 - link

    the last page is missing Reply
  • Coup27 - Tuesday, April 10, 2012 - link

    also all easter weekend I've had rendering issues with the comments section. It doesn't load up correctly and it's like a text version instead of html. This has happened on 3 different PC's so I think its something with the site. Reply
  • Ryan Smith - Tuesday, April 10, 2012 - link

    What browser are you on? To the best of my knowledge we are not currently having any site issues, and at the moment the comments section is working fine for me. Reply
  • bji - Tuesday, April 10, 2012 - link

    A similar thing happened for me too with several stores in the past few days. The comments section would show up without indentation (all comments lined up at the left) and comments would be separated by some weird looking title bar (looked a little like an Apple candy theme thing from the early 2000's, only clunkier). A reload of the page would bring it back to the normal view. My browser is Firefox on Linux. Reply
  • bji - Tuesday, April 10, 2012 - link

    stores -> stories Reply
  • Hockster - Wednesday, April 11, 2012 - link

    I'm using the latest Firefox and don't see the last page either. Reply
  • Hockster - Wednesday, April 11, 2012 - link

    Oops, didn't realize there wasn't a conclusion page. Reply
  • Ryan Smith - Tuesday, April 10, 2012 - link

    Actually the last page is there; it just isn't a conclusion page. We went with something a bit different this time and did an abridged review since it's using a controller & NAND we've already reviewed. The first page is the complete review from an editorial standpoint, while the following pages are all of the benchmarks and analysis.

    -Thanks
    Ryan Smith
    Reply
  • Coup27 - Tuesday, April 10, 2012 - link

    tbh I missed that. I hadn't read the article and thought the end had been chopped off by this rendering issue. I have just uploaded a screenshot of what happens. This is the 4th PC in 3 different places it's happened on so it must be the site:

    http://www.elmleigh.co.uk/Paul/ATissue.jpg
    Reply
  • Ryan Smith - Tuesday, April 10, 2012 - link

    Humm, from that screenshot it looks like you're not getting part or all of the main style sheet. All I can really suggest is flushing your cache and disabling any add-ons. The style sheet is being served up correctly and hasn't changed in the better part of the last year.

    http://www.anandtech.com/content/main.css
    Reply

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