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IOMeter — Sequential and random performance
IOMeter fuels much of our latest storage test suite, including our sequential and random I/O tests. These tests are run across the full capacity of the drive at two queue depths. The QD1 tests simulate a single thread, while the QD4 results emulate a more demanding desktop workload. For perspective, 87% of the requests in our old DriveBench 2.0 trace of real-world desktop activity have a queue depth of four or less. Clicking the buttons below the graphs switches between results charted at the different queue depths.

Our sequential tests use a relatively large 128KB block size.



The Reactor's sequential speeds are excellent. Only PCIe drives read appreciably faster. Samsung's 850 EVO 1TB handles writes about 15% faster than the Reactor, but that's not a huge margin of victory for a substantially more expensive drive. The Reactor's write performance is right on par with the other couple of 1TB-class SATA drives in the dataset: OCZ's Vector 180 and Transcend's SSD370.

Next, we'll turn our attention to performance with 4KB random I/O. The tests below are based on the median of three consecutive three-minute runs. SSDs typically deliver consistent sequential and random read performance over that period, but random write speeds worsen as the drive's overprovisioned area is consumed by incoming writes. We've reported average response times rather than raw throughput, which we think makes sense in the context of system responsiveness.



The Reactor's random read response times are smack dab in the middle of the pack at both queue depths. Its random write latencies are at the top end of our data set, which is par for the course with a drive this size. So far, so good. In spite of its budget price tag, the Reactor is performing remarkably well.