Re: Opteron vs. Xeon performance differences

On Thu, 9 Oct 2008, Bart Grantham wrote:

> The full story: we have an older production server with 2G of RAM,
> 2.4GHz Opterons w/ 1M of cache...The newer servers have 4G of RAM,
> 3.0GHz Xeons with 2M of cache.

Model numbers please?  I can probably guess for the Opterons, there are a
lot of different implementations lumped under the Xeon brand name.

Have you taken compared how fast the RAM is in the two systems?  We were
just talking about a similar unexpected performance different yesterday on
another list:
http://archives.postgresql.org/pgsql-performance/2008-10/msg00051.php

I'd be curious what memtest86+ and the simple hdparm -T benchmark say
about the two servers.  If those numbers correlate with the performance
difference you're seeing, the PostgreSQL code might have nothing to do
with it.  I've seen a 60% performance difference just between the best and
worst RAM I tried on a single motherboard recently.

--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD