Sequential Read/Write Performance

To measure sequential read and write performance I created an iometer test script to read and write 2MB files to the drives. The writes are 100% sequential and are performed on an unpartitioned drive for 3 minutes.

Performance is reported in MB/s, higher numbers are better.

The sequential read performance of the latest generation of SSDs is nothing short of amazing. The OCZ Vertex pulls through with 250MB/s, over twice the speed of the VelociRaptor and 2.5x the speed of the Samsung SLC drive that OCZ used to sell for $1000.

Looking at write performance we see things change a bit. The OCZ Summit and Intel X25-E are the only two drives that can outperform the VelociRaptor, and they do so handsomely. The rest of the drives fall below even the 7200 RPM Caviar SE16. They are by no means slow, they just don't destroy the fastest hard drives as they do in other tests.

While the X25-E should perform the way it does, the OCZ Summit uses MLC flash yet it performs like an SLC drive. This is a very important benchmark as it shows the sort of performance Samsung has optimized for with its controller. This drive is designed to shatter bandwidth barriers, but what about latency?

The Test Random Read/Write Performance
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  • blackburried - Wednesday, March 25, 2009 - link

    It's referred to as "discard" in the kernel functions.

    It works very well w/ SSD's that support TRIM, like fusion-io's drives.
  • Iger - Wednesday, March 25, 2009 - link

    This is the best review I've read in a very long time.
    Thank you very much!
  • BailoutBenny - Tuesday, March 24, 2009 - link

    Great in depth article on flash based SSDs. I'm waiting for PRAM though.
  • orclordrh - Tuesday, March 24, 2009 - link

    Very illuminating article, very well written and researched. It made me glad that I didn't pull the trigger on an SSD for my I7 machine and regret not buying OCZ memory! I'm interested in adding an SSD as the scratch disk for Photoshop CS4 to use. I don't really launch applications very often, say once a week on the weekly reboot and keep 6-8 apps open at all times. I have 12GB of memory for that. The benchmarks were very interesting, but what sort of activity does Photoshop scratch usage create? Large files or random writes? What type of SSD would be most cost effective here?
    An SSD does sound better than a SSD!
  • semo - Wednesday, March 25, 2009 - link

    wait for ddr3 to enter the mainstream and buy loads of memory.

    use a ramdisk for your adobe scratch area. much faster than ssd and no wear to worry about (not that you would worry that much with modern ssds anyway).

    http://www.ghacks.net/2007/12/14/use-a-ramdisk-to-...">http://www.ghacks.net/2007/12/14/use-a-ramdisk-to-...

    there is also a paid for and more feature rich ramdisk out there. can't remember the name
  • strikeback03 - Wednesday, March 25, 2009 - link

    I'll have to check when I get home, but I believe the recommended size for the scratch disk is upwards of 10GB. So would need a motherboard that supports a LOT of RAM to give enough to main memory plus a scratch disk.
  • strikeback03 - Wednesday, March 25, 2009 - link

    I was wondering the same thing. I'd guess it would be a lot of writing/erasing, so an SSD might not be the best from a longevity standpoint, but if your system is hitting the scratch disk often then the speed might make it worthwhile.
  • mikepers - Tuesday, March 24, 2009 - link

    Anand,

    I wanted to compliment you on what I think was an excellent article. This is the type of thing I really have always liked from Anandtech. The detailed background, the technical reasons for the issues and then a thorough review of the current state of things.

    I just finished upgrading my desktop. The only remaining item I wanted to replace was the hard disk. I had been thinking about getting a Velociraptor but instead I just ordered a 60GB Vertex from Newegg.

    Thanks again for all the work.

    Mike P.
  • ameatypie - Monday, March 23, 2009 - link

    That sure was a lot to take in! Fantastic article though, it has really opened my eyes to the possibilities that Solid State Drives provide. Probably wont be buying one in the immediate future given the so-called depression and such things, but i will certainly keep up with SSD progress.
    Thanks again for your fantastic articles - im sure im not the only one who really appreciates them :)
  • coopchennick - Monday, March 23, 2009 - link

    Hey Anand, I just finished reading through this whole article and I'm very impressed with the thoroughness and how informative it was.

    You just acquired a new regular reader.

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