--- On Mon, 11/4/11, da...@lang.hm <da...@lang.hm> wrote: > From: da...@lang.hm <da...@lang.hm> > Subject: Re: [PERFORM] Linux: more cores = less concurrency. > To: "Steve Clark" <scl...@netwolves.com> > Cc: "Scott Marlowe" <scott.marl...@gmail.com>, "Joshua D. Drake" > <j...@commandprompt.com>, "Kevin Grittner" <kevin.gritt...@wicourts.gov>, > pgsql-performance@postgresql.org, "Glyn Astill" <glynast...@yahoo.co.uk> > 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 (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
