--- On Mon, 11/4/11, [email protected] <[email protected]> wrote: > From: [email protected] <[email protected]> > Subject: Re: [PERFORM] Linux: more cores = less concurrency. > To: "Steve Clark" <[email protected]> > Cc: "Scott Marlowe" <[email protected]>, "Joshua D. Drake" > <[email protected]>, "Kevin Grittner" <[email protected]>, > [email protected], "Glyn Astill" <[email protected]> > Date: Monday, 11 April, 2011, 21:04 > On Mon, 11 Apr 2011, Steve Clark > wrote: > > the limit isn't 8 cores, it's that the hyperthreaded cores > don't work well with the postgres access patterns. >
This has nothing to do with hyperthreading. I have a hyperthreaded benchmark purely for completion, but can we please forget about it. The issue I'm seeing is that 8 real cores outperform 16 real cores, which outperform 32 real cores under high concurrency. 32 cores is much faster than 8 when I have relatively few clients, but as the number of clients is scaled up 8 cores wins outright. I was hoping someone had seen this sort of behaviour before, and could offer some sort of explanation or advice. -- Sent via pgsql-performance mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
