Results: Sequential Performance
Once again, we turn to Iometer to measure the most basic performance parameters.
Fantastic sequential read and write performance is a trademark of modern SSDs. To measure it, we use incompressible data over a 16 GB LBA space and then test at queue depths from one to 16. We're reporting these numbers in binary (where 1 KB equals 1024) instead of decimal (where 1 KB is 1000 bytes). When necessary, we're also limiting the scale of the chart to help readability.
128 KB Sequential Read Scaling
Just about every newer SSD ends up beyond the 500 MB/s mark with eight or 16 outstanding commands. The most notable differences come into play at lower queue depths, particularly when the queue depth is one or two.
The SanDisk drives peak past two outstanding commands, laying down a fierce 530+ MB/s. They best the next-fastest repositories, though not by much. Even at a queue depth of one, the Extreme IIs push 500 MB/s.
128 KB Sequential Write Scaling
Again, the SanDisk trio shows up swinging. The 240 and 480 GB models both touch 500 MB/s on writes, while the 120 GB version makes a splash by achieving 316 MB/s. That's actually the upper range for a 120 GB SSD, unless you're taking about a SandForce-based drive working on zero-fill data, and the most junior Extreme is on par with Intel's SSD 510 and 335 with two times the capacity.
Performance Versus Capacity
There aren't many surprises to see when we look at capacity across the LBA range. In truth, this chart should be a flat line across the entire drive. In reality, not every SSD behaves that way.
And that's exactly what we see. The Extreme IIs are seemingly wedded together, separated by just a few MB/s.
A similar story is told when we look at writes (that is to say, not a very interesting one). The larger two models are almost as quick as each other, while the 120 GB version kisses 320 MB/s. It's possible that the comparatively jagged performance line is a result of nCache.
