Linux I/O Scheduler Comparison On The Linux 3.4 Desktop
Phoronix: Linux I/O Scheduler Comparison On The Linux 3.4 Desktop
At the request of Phoronix readers, and that the default I/O scheduler may change, here's a comparison of the CFQ, Deadline, and Noop schedulers on three systems and covering both rotating media (HDD) and solid-state storage (SSDs).
What about BFQ? zen-stable maintains a branch that's just BFQ on top of mainline, in case you want to try that: http://git.zen-kernel.org/zen-stable/log/?h=3.3/bfq
Been using Deadline with my 60MB SSD with Arch. I may switch back to CFQ based upon this article. Thanks Michael, for yet another informative article.
What about BFQ ?
Can you say anything about the responsiveness during the benchmarks? I do not care, if my SSD needs 1 or 2 seconds to save/read something but it bothers me if other devices, especially input, suffer through the process...
What about responsiveness?
For years I've had problems using the desktop while a intensive IO operation is running. Even when simply transferring file to pendrive.
Hard to benchmark well
This is the kind of thing where looking at throughput numbers can easily deceive someone. If you're running a multimedia system (e.g. mythtv) then throughput it the least of your concerns, and the stuff you actually care about, isn't on these graphs at all. Not saying Michael has done badly here (what else could he have done?) but it might have been a waste of time.
Some other site covered the issue.
Originally Posted by talvik
I don't think we will see anything like it on Phoronix, but framejitter and uneven load is fairly important issues.