On Mon, Oct 8, 2012 at 8:03 PM, Craig James <cja...@emolecules.com> wrote: >> > But again ... the two systems are identical. This can't explain it. >> >> Is the read-ahead the same in both systems? > > > Yes, as I said in the original reply (it got cut off from your reply): "Same > on both servers."
Oh, yes. Google collapsed it. Wierd. Anyway, sequential I/O isn't the same in both servers, and usually you don't get full sequential performance unless you bump up the read-ahead. I'm still betting on that for the difference in sequential performance. As for pgbench, I'm not sure, but I think pgbench doesn't really stress sequential performance. You seem to be getting bad queueing performance. Did you check NCQ status on the RAID controller? Is it on on both servers? -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
