From: David Boreham <david_list@boreham.org>
To: pgsql-performance@postgresql.org
Subject: Re: HT on or off for E5-26xx ?
Date: Wed, 07 Nov 2012 06:33:19 -0700
Message-ID: <509A631F.2010507@boreham.org> (raw)
In-Reply-To: <5099E094.9010703@catalyst.net.nz>
References: <5099D5FA.90802@boreham.org>
<5099E094.9010703@catalyst.net.nz>
On 11/6/2012 9:16 PM, Mark Kirkwood wrote:
>
>
> I've been benchmarking a E5-4640 (4 socket) and hyperthreading off
> gave much better scaling behaviour in pgbench (gentle rise and flatten
> off), whereas with hyperthreading on there was a dramatic falloff
> after approx number clients = number of (hyperthreaded) cpus. The box
> is intended to be a pure db server, so we are running with
> hyperthreading off.
It looks like this syndrome is not observed on my box, likely due to the
much lower number of cores system-wide (12).
I see pgbench tps increase nicely until #threads/clients == #cores, then
plateau. I tested up to 96 threads btw.
We're waiting on more memory modules to arrive. I'll post some test
results once we have all 4 memory banks populated.
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To: pgsql-performance@postgresql.org
Cc: david_list@boreham.org
Subject: Re: HT on or off for E5-26xx ?
In-Reply-To: <509A631F.2010507@boreham.org>
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