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

Recently I published a number of Linux 5.0 I/O scheduler benchmarks on laptop and desktop hardware with solid-state storage. A number of Phoronix readers were interested in seeing similar tests done but with traditional hard drives, so here are those results using two different drives and the different blk-mq I/O scheduler options with the new Linux 5.0 kernel.

Tested off an Ubuntu 18.10 installation after upgrading to the Linux 5.0 kernel were a Western Digital Green WD5000AZRX 500GB hard drive as a conventional SATA 3.0 HDD drive with 64MB cache as well as a Western Digital VelociRaptor WD1500HLHX 150GB drive. The VelociRaptor at 10k RPM has more performance potential out of these SATA 3.0 hard drives albeit with only a 32MB cache compared to 64MB on the WD Green drive being used. With both drives, the following multi-queue I/O schedulers were tested:

- Mq-deadline (the default for HDDs on Ubuntu and most other Linux distributions)
- None (no I/O scheduler)
- Kyber (the new-ish Facebook-developed I/O scheduler)
- BFQ low-latency (the default BFQ mode)
- BFQ (BFQ when disabling the low-latency mode to favor higher throughput)

Via the Phoronix Test Suite a range of storage benchmarks were then carried out for looking at these two hard drives with the five I/O scheduler options off Linux 5.0.