On Wed, Oct 27, 2010 at 12:28 PM, Scott Marlowe <scott.marlowe@xxxxxxxxx> wrote: > On Wed, Oct 27, 2010 at 12:03 PM, Josh Berkus <josh@xxxxxxxxxxxx> wrote: >> On 10/26/10 6:14 PM, Scott Marlowe wrote: >>> There was an earlier thread with >>> Greg and I in it where we posted the memory bandwidth numbers for that >>> machine and it was insane how much data all 48 cores could pump into / >>> out of memory at the same time. >> >> Well, the next step then is to do some database server benchmarking. >> >> My experience has been that PostgreSQL scales poorly past 30 cores, or >> even at lower levels depending on the workload. So it would be >> interesting to see if the memory bandwidth on the AMDs makes up for our >> scaling issues. > > Which OSes have you tested it on? And what hardware? For smaller > operations, like pgbench, where a large amount of what you're working > on fits in cache, I get near linear scaling right up to 48 cores. > Overall performance increases til about 50 threads, then drops off to > about 60 to 70% peak for the next hundred or so threads I add on. And that's with 8.3.latest on ubuntu 10.04 with latest updates on HW RAID. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
