Re: Linux: more cores = less concurrency.

On 04/11/2011 02:32 PM, Scott Marlowe wrote:

On Mon, Apr 11, 2011 at 12:12 PM, Joshua D. Drake <jd@commandprompt.com> wrote:

On Mon, 11 Apr 2011 13:09:15 -0500, "Kevin Grittner"
<Kevin.Grittner@wicourts.gov> wrote:

Glyn Astill <glynastill@yahoo.co.uk> wrote:

The new server uses 4 x 8 core Xeon X7550 CPUs at 2Ghz

Which has hyperthreading.

our current servers are 2 x 4 core Xeon E5320 CPUs at 2Ghz.

Which doesn't have hyperthreading.

PostgreSQL often performs worse with hyperthreading than without.
Have you turned HT off on your new machine?  If not, I would start
there.

Anyone know the reason for that?

And then make sure you aren't running CFQ.

JD

This++

Also if you're running a good hardware RAID controller, jsut go to NOOP