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)

Random read performance is staggering - a good 40% higher than anything else we've tested. While the cutoff for usefulness on a client drive is likely much lower than what even the Octane could deliver, this sort of performance bodes very well for OCZ's enterprise ambitions.

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

Randomly write performance is also just excellent. SandForce's peak numbers come close, but throw in any sort of incompressible data and they quickly take a step back while the Vertex 4 is able to deliver. Again, I'm actually more interested in these numbers from an enterprise workload standpoint but heavy client users will definitely not be disappointed.

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)

SandForce always scaled well at higher queue depths, but again we're looking at best case performance for the SF-2281. Move towards incompressible data and the Vertex 4 is alone at the top.

Inside the Vertex 4 Sequential Read/Write Speed
Comments Locked

127 Comments

View All Comments

  • elghosto - Wednesday, April 4, 2012 - link

    linux
    #fstrim
  • Per Hansson - Wednesday, April 4, 2012 - link

    "monitoring port of the SSD"
    Please enlighten me, Google was no help...
    Is it a hardware interface that allows you to see how the drive operates?
  • adamantinepiggy - Thursday, April 5, 2012 - link

    Basically, every SSD has some sort of real-time data port that allows engineers to monitor what is going on with the SSD, even when the drive hangs or has other issues. It is used mainly for development/testing. Consider it sorta like a way to read/access the dump file when Windows BSOD's, except in this case it's on the SSD. This monitoring port gets disabled on released drive firmware and the hardware attachment leads are unattached..
  • jonup - Wednesday, April 4, 2012 - link

    Thanks for asking this! I always wanted to know that myself. I actually google it to no avail while I was reading the article.
  • medys - Wednesday, April 4, 2012 - link

    How long till we are overclocking our SSD processors :-/
  • FunBunny2 - Wednesday, April 4, 2012 - link

    Umm. How you gonna fit that water cooler inside the case?
  • Iketh - Wednesday, April 4, 2012 - link

    hahaha... NEVER!! I've yet to break a Win7 installation from overclocking, but I broke XP many times... I shudder at the thought of overclocking an SSD :)
  • Iketh - Wednesday, April 4, 2012 - link

    Although, I wonder how long until the processors in SSDs reach, say, today's single-core Atom... OR better yet, how long before the SSD controller is built into the CPU much like the memory controller, where we install more storage the same way we install ram... and then later again the nand controller and RAM controller merge, and a computer is nothing more than a SoC with some nand sitting next to it...
  • iwod - Wednesday, April 4, 2012 - link

    We finally have controller that are able to bump out MB faster then Sandforce without using some silly compression engine. Marvell also announced next Gen SSD controller as well.

    Again we have reached the limit of SATA 6Gbps, we will need to start thinking about SATA Express, Lower power consumption, reliability. etc...
  • akbo - Wednesday, April 4, 2012 - link

    Though I think the high consumption might be because of the controller, the chip is huge! With thermy sticky!

    Wonder when a die shrink of this is possible.

Log in

Don't have an account? Sign up now