[amluto]

This reminds me: if you're stuck on a Linux kernel before 3.9 and you're using Sandy Bridge hardware or newer, turn off C1E in BIOS. The "C1E" setting controls a misfeature in which the CPU will look at the OS's request for a light sleep and say "Ha! You must have asked for light sleep by accident! I'm going to go all the way to sleep instead!" This causes surprisingly severe performance problems (we've seen milliseconds of unexplained random hiccups).

Linux 3.9 and higher is immune: it just forcibly disables this feature.

[makomk]

Hah. I guess that's a major benchmark win - decreases power usage in common cases, and few CPU benchmarks test wake-from-sleep latency either directly or indirectly.