Benchmark Results: 4 KB And 512 KB Random Reads
Testing random read and write speed is perhaps most important for desktop usage models. Unless you’re doing heavy video editing, you’re probably not reading or writing a ton of sequential data to an SSD, after all.
Intel pulls far ahead in Iometer's 4 KB random read performance, while the Agility 2 and Vertex 2 match one another. Seagate's Momentus 5400.6 falls into last place here.
The header of these two charts is the same, except for one important detail. The first employs a queue depth of one, and the second uses a queue depth of 32. Why are these figures important? Well, look what they do to performance.
Native Command Queuing, part of the SATA specification, was originally designed to improve the performance of mechanical disks by allowing the hard drive itself to optimize the order in which read and write commands get executed. Of course, the physics of a hard drive don’t apply to SSDs. However, the multi-channel architecture of a solid state drive enables it to similarly field multiple concurrent requests—though Intel claims the bottleneck isn’t the drive, but rather the host system itself. Today’s SSDs are consequently dependent on high queue depths in order to realize the specifications you see manufacturers quoting.
With a QD of one, it's easy to see how reliant Intel's architecture is on concurrent requests, as both the SandForce- and Toshiba-based drives outperform the SSD 310. Cranking queue depth up to the other (very unrealistic on the desktop and even more so in a mobile environment) extreme queue depth of 32, Intel's 310 is suddenly pushing 157 MB/s, passing its competition by a notable margin. That's incredibly optimistic, though, especially for a product designed to address embedded and netbook markets.
