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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  • NetCommercial - Thursday, November 22, 2012 - link

    Long time reader just signed up to comment as it appears you actually read them and do take into consideration the comment itself.
    First off thank you for the benchmarks and simplifying the results the best you can. I enjoyed the article showing the Kingston X that is on sale at Newegg for BFriday and was considering it.
    After reading I will pass. I am a video editor. I think a good percentage of us are in some way using our computers for more then gaming. After all the rigs people are putting together are ridiculous for gaming. I play games online and get kicked all the time for being too 'fast'. That is with a dinosaur of a pre-made Dell bucket.
    With that being stated I would like to see an area where you guys do shoot outs with the same sized/priced equipment doing renders with decent sized files. For instance the review did on the King x was terrific however where was Plextor @ ? It is in the price range and does compete with the Sammy 830/ 840pro IMO... This article just started to brief on that scenario.
    Again Thank you for your help, advice and time you put into these articles. You are one of my resource hubs of trusted information.
    Best,
    NetCommercial
    Reply
  • ickibar1234 - Monday, December 02, 2013 - link

    The Desktop IOMeter 4K random read of only 40MB/s is kind of sad. I'm sure that is with a queue depth of 1 but still. Reply

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