Linux 4.17 I/O Scheduler Tests On An NVMe SSD Yield Surprising Results

The fastest FS-Mark performance was found to be with MQ-Deadline and BFQ.

While for the multi-threaded Dbench test case, mq-deadline and none were tied for the fastest results.

With IOzone writes, the fastest was again with BFQ and MQ-Deadline while the slowest write performance was using Kyber.

While carrying out sixteen concurrent writes with the Threaded I/O Tester, using no I/O scheduler or MQ-Deadline was the fastest.

These were certainly some interesting I/O scheduler tests for the Intel Optane 900p SSD when most Linux distributions opt for "none" with NVMe storage. Of the 17 tests ran, BFQ low_latency and "none" tied for first with five wins each followed by mq-deadline and then BFQ. The Kyber I/O scheduler was the only one not to have a single outright win, although it was effectively tied for first in some cases.

While BFQ low_latency tied for having the most wins, it led with the greatest number of losses in the throughput tests where it came in last six times followed by Kyber five times and the others each with two losses.

Coming up soon will be similar Linux 4.17 I/O scheduler tests but when carrying out the tests on conventional SATA 3.0 SSDs and HDDs.