I was bored and ran some quick and possibly not very accurate throughput tests on I/O schedulers with iozone.
The tests were done on a PCIe x2 NVME SSD, btrfs filesystem with no compression.
The Y-axis is in KBytes/s, fsync() not taken into account.
Yes, that’s what I thought as well, still valid as it seems.
However this is just a throughput test, for a more complete picture we would have to run other tests (e.g. latency) as well.
Unfortunately this drive is btrfs only and has no free space left…