What does HackerNews think of fio?

Flexible I/O Tester

Language: C

Not specifically addressing your question, but when you get to the point of wanting to start doing some experiments you may find that 'fio' [1] is very handy.

[1] https://github.com/axboe/fio

hdparm is an "okay" tool for a quick read speed benchmark, but if you really want to benchmark Linux storage, its hard to beat fio[0]

[0] https://github.com/axboe/fio

This use of dt, etc, is pretty cool, and I understand the point of this this blog entry was an exploration of those tools.

But in the wider world of SSD performance, you're going to want more. fio (written by Jens Axboe, who's responsible for a lot of the I/O subsystem in Linux) is the standard tool used to do benchmarking, has tons of options to control I/O mix and parallelism, captures both thruput and latency numbers, with lots of switches to control exactly what data is collected. https://github.com/axboe/fio

"Something weird going on with the 1K bucket landing at the bottom." The SSD's Flash Translation Layer will occasionally do both caching and garbage collection, leading to the weird extreme long latency outlier. The long spike at 1K is weird, but note that optimal internal write size of the SSD is probably something like 64K or 128K these days. Different SSDs will have different FTL algorithms, different overprovisioning, different internal parallelism, etc, so it can be very tricky predict actual real-life performance. https://en.wikipedia.org/wiki/Flash_memory_controller