Mendola Gaetano wrote:
> Hi all,
> we are going to move our production postgres box ( on Linux )
> in a new machine, I'm wondering if I shall leave the Hyperthreading
> feature on or disable it.
> Anyone have experience on this?
Just FYI.
We turned Hyperthreading off for our production *dual* Xeon box. This is
mainly because we're on Linux 2.4.9 (+ Red Hat's patches for Advanced
Server). We've yet to see conclusive evidence that Linux 2.4.9 can take
dual Hyperthreaded processors into account, therefore we disabled it.
Please note emphasis on DUAL Hyperthreaded processors. If we have
processors A and B, Linux will see it as, say, A1, A2, B1, B2. We can't
tell if this version of Linux will not try to run two 100% CPU bound
processors on A1, and A2, while letting real processor B idle.
Didn't matter much in the end anyway, because postgresql handled our
load just fine on two real processors.
--
Linux homer 2.4.18-14 #1 Wed Sep 4 13:35:50 EDT 2002 i686 i686 i386
GNU/Linux 10:30am up 202 days, 1:35, 6 users, load average: 5.40, 5.14, 5.05