Re: Performance problems on 4/8way Opteron (dualcore)

I've been running 2x265's on FC4 64-bit (2.6.11-1+) and it's been
running perfect. With NUMA enabled, it runs incrementally faster than
NUMA off. Performance is definitely better than the 2x244s they replaced
-- how much faster, I can't measure since I don't have the transaction
volume to compare to previous benchmarks. I do see more consistently low
response times though, can run apache also on the server for faster HTML
generation times and top seems to show in general twice as much CPU
power idle on average (25% per 265 core versus 50% per 244.)

I haven't investigated the 2.6.12+ kernel updates yet -- I probably will
do our development servers first to give it a test.

> The problem as I remember it boiled down to the Linux kernel handling
> memory/process management very badly on large dual core systems --
> pathological NUMA behavior. However, this problem has apparently been fixed
> in Linux v2.6.12+, and using the more recent kernel on large dual core
> systems generated *massive* performance improvements on these systems for
> the individuals with this issue. Using the patched kernel, one gets the
> performance most people were expecting.