On Tue, Jul 21, 2009 at 3:16 PM, Scott Marlowe<scott.marlowe@xxxxxxxxx> wrote: > On Tue, Jul 21, 2009 at 6:42 AM, Doug Hunley<doug@xxxxxxxxxxxxxxxxx> wrote: >> Just wondering is the issue referenced in >> http://archives.postgresql.org/pgsql-performance/2005-11/msg00415.php >> is still present in 8.4 or if some tunable (or other) made the use of >> hyperthreading a non-issue. We're looking to upgrade our servers soon >> for performance reasons and am trying to determine if more cpus (no >> HT) or less cpus (with HT) are the way to go. Thx > > This isn't really an application tunable so much as a kernel level > tunable. PostgreSQL seems to have scaled pretty well a couple years > ago in the tweakers.net benchmark of the Sun T1 CPU with 4 threads per > core. However, at the time 4 AMD cores were spanking 8 Sun T1 cores > with 4 threads each. > > Now, whether or not their benchmark applies to your application only > you can say. Can you get machines on a 30 day trial program to > benchmark them and decide which to go with? I'm guessing that dual > 6core Opterons with lots of memory is the current king of the hill for > reasonably priced pg servers that are running CPU bound loads. > > If you're mostly IO bound then it really doesn't matter which CPU. Unless he is doing a lot of computations, on small sets of data. Now I am confused, HT is not anywhere near what 'threads' are on sparcs afaik. -- GJ -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
