Linux 5.0 HDD I/O Scheduler Benchmarks - BFQ Takes The Cake

While measuring the time to launch xterm with sequential reads happening in the background, BFQ did very well similar to the SSD results. BFQ in its low-latency mode yields a much more responsive system compared to the other scheduler options, but even this Budget Fair Queuing scheduler in its non-low-latency mode did still perform well and better than the other I/O schedulers benchmarked on these two consumer HDDs.

While launching xterm again with both reads and writes happening in the background, BFQ still did an exceptional job providing a responsive Linux desktop.

With the basic SQLite embedded database library benchmark, there wasn't much variation between the I/O schedulers with the WD VelociRaptor but none and BFQ low-latency tended to do the best on the WD "Green" drive while Kyber and Mq-deadline were slower albeit with some wild swings in variation between runs.

Random writes yielded similar performance on the VelociRaptor HDD between Mq-deadline, Kyber, and BFQ while BFQ's low-latency and using no I/O scheduler led to lower random write speeds.

For sequential writes, BFQ in its throughput mode was performing very well albeit with a fair amount of noise to these particular results.