"Brandon Metcalf" <bmetcalf@xxxxxxxxxx> writes: > We've been tuning the kernel (2.4 SMP flavor) and have improved > performance quite a bit. I'm now wondering if turning off HT will > improve performance even more. Based on the vmstat output below, is > the context switching typical or too high? Given that your CPU usage is hovering around 2%, it's highly unlikely that you'll be able to measure any change at all by fiddling with HT. What you need to be working on is disk I/O --- the "80% wait" number is what should be getting your attention, not the CS number. (FWIW, on the sort of hardware you're talking about, I wouldn't worry about CS rates lower than maybe 10000/sec --- the hardware can sustain well over 10x that.) regards, tom lane
