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Sustained and scaling I/O rates
Our sustained IOMeter test hammers drives with 4KB random writes for 30 minutes straight. It uses a queue depth of 32, a setting that should result in higher speeds that saturate each drive's overprovisioned area more quickly. This lengthy—and heavy—workload isn't indicative of typical PC use, but it provides a sense of how the drives react when they're pushed to the brink.

We're reporting IOps rather than response times for these tests. Click the buttons below the graph to switch between SSDs.

To show the data in a slightly different light, we've graphed the peak random-write rate and the average, steady-state speed over the last minute of the test.

Well, that's a particularly low peak. For context, the Vector 180's steady-state speeds were almost half the VX500's peak speeds. But we don't really care so much about the actual magnitude of the peak, since the point of the test is to examine how drives perform once they've exhausted all their tricks. The VX500's steady-state speeds land in the good company of the 850 EVO 250GB and BX100 500GB once its pseudo-SLC cache is saturated.

Our final IOMeter test examines performance scaling across a broad range of queue depths. We ramp all the way up to a queue depth of 128. Don't expect AHCI-based drives to scale past 32, though—that's the maximum depth of their native command queues.

For this test, we use a database access pattern comprising 66% reads and 33% writes, all of which are random. The test runs after 30 minutes of continuous random writes that put the drives in a simulated used state. Click the buttons below the graph to switch between the different drives. And note that the P3700 plot uses a much larger scale.

The VX500 flatlines around QD4, but that's par for the course for your average consumer drive. After all, the lion's share of the standard consumer workload happens at QD4 or lower. Let's see how the VX500 looks against a selection of other drives.

In line with expectations: a good bit better than the Trion 150, but a far cry from the carefully binned and validated chips in the Vector 180. The VX500 scales similarly to Crucial's MX200, its 500GB-class MLC contemporary.

IOMeter exposed some rather disappointing sequential write performance from the VX500, but maybe a real-world workload will better play to the drive's strengths. Let's find out with TR RoboBench.