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

Random write speed is improved compared to the 510 thanks to Intel's controller, but we're only looking at a marginal improvement compared to the original X25-M G2.

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

Iometer - 4KB Random Read, QD=3

Random read performance has always been a strong point of Intel's controller and the 320 is no different. While we're not quite up to C300 levels, the 320 is definitely competitive here.

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.

Iometer - 128KB Sequential Write

Without a 6Gbps interface the 320's performance is severely limited. Compared to other 3Gbps drives the 320 is quite good here though.

Iometer - 128KB Sequential Read

Read performance is at the top of the chart for 3Gbps drives. I wonder how far Intel would've been able to push things if the 320 had a 6Gbps controller.

Spare Area, 3Gbps Only, AES-128 AnandTech Storage Bench 2011: Much Heavier


View All Comments

  • bji - Tuesday, March 29, 2011 - link

    I think that garbage collection refers to a process of deferring block erases to a later time to be done when the drive is otherwise idle. I.e., if you need to rewrite a block you don't re-write it in place, you write it to a block from the spare area that is already cleared thus saving yourself the time of having to erase the old block before rewriting it. You still mark the old block as needing to be cleared and put into the spare area (to replace the block that was taken out of the spare area during this process), and you do that later during 'garbage collection'.

    There may also be some aspects to which individual blocks from an erase region (my understanding of the terminology is a bit off but I am pretty sure that flash memory can write to smaller regions than it can erase) are moved around during 'garbage collection' to consolidate them into single blocks; this takes blocks that are interspersed with dead area and collapses them down to a smaller fully populated region, then takes all of the now-free blocks and then erases them and puts them in the spare area.

    Having TRIM makes both of these processes more efficient because it tells the drive that it can just mark blocks as ready-for-erase-and-put-into-the-spare-area immediately rather than having to be tracked and managed, and also increases the overall spare area available which means that more already-erased blocks are ready to be used for writes. Having to erase a block before writing it is the performance killer of SSDs and TRIM, along with intelligent algorithms listed above, in addition to things I haven't even thought of most likely, are what allow SSDs to get around the erase block performance penalty and to have such killer performance.
  • randomlinh - Monday, March 28, 2011 - link

    I was excited to see this back when it was "announced." I was hoping we'd be closer to $1/GB for the mainstream performance around now, but looks like I've still got to wait.

    Hoping the 2011 round of controllers push intel to compete with pricing. I'm happy with the performance honestly, but need pricing.

    Or maybe this will drive the x25-Ms down in price and I'll just RAID-0 a pair of 80GB's...
  • Ushio01 - Monday, March 28, 2011 - link

    So all we get from Marvel and Intel are there old controllers working as they should of from the beginning with only Sandforce actually innovating, pathetic. Reply
  • darckhart - Monday, March 28, 2011 - link

    "should have been" maybe. but we all know that's not how business works. sell it, revise it, sell it, revise it, ad nauseum. in any case, know this: they are getting comparable SF-12xx performance WITHOUT realtime compression and dedup which is mighty impressive in my book. Reply
  • darckhart - Monday, March 28, 2011 - link

    oh i forgot to mention they're doing this on 25nm. Reply
  • Vlad T. - Monday, March 28, 2011 - link

    Planned obsolescence or built-in obsolescence.


    That is even more obvious considering how Intel trashes G2 with the same controller.
  • thudo - Monday, March 28, 2011 - link

    My gawd how the mighty have fallen? Doesn't remotely hold its own against the mighty Vertex 3 (SATA3). 120Gb Vertex 3 as now showing up in Canada for ~$290 -- a frick'n steal considering my boot drives have always been ~100-150Gb+ (all you need) and the performance increase is so well worth it. Shame Intel.. shame.. Reply
  • davepermen - Monday, March 28, 2011 - link

    you know that intel has the 520 ssds, too? those are to fight vertex3.

    not that i would ever consider ocz an ssd worth buying anyways, but lets not discuss that. anand loves them after he hated them. i still can't (as even after anand has forgiven them, they continue the same crap they did before).

    so for a sata3 system, it's 520. for a sata2 system, the 320 is fine, actually nearly perfect.
  • sean.crees - Tuesday, March 29, 2011 - link

    Say what you will of OCZ, at least they listen to their consumers, and attempt to make legitimate changes in their business practices to satisfy their existing customer base.

    Intel has it's advantages, but appeasing it's current customers are not one of them. Ask the numerous amounts of people that jumped on Intel's 1st gen SSD bandwagon to then be shunned from TRIM support forever, which would require nothing but a firmware upgrade. 2x 80gb for $500 each, and no TRIM support. These things have slowed to almost HDD performance.
  • shatteredx - Monday, March 28, 2011 - link

    Performance is fine, but Intel isn't pricing these drives cheaply enough.

    Whatever happened to the prediction that 25nm drives would cost half as much as their 34nm siblings?

Log in

Don't have an account? Sign up now