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@xxxxxxxxxxxxx http://www.gregsmith.com Baltimore, MD
