Re: Large (8M) cache vs. dual-core CPUs

["Jim C. Nasby" <jnasby(at)pervasive(dot)com>]

On Tue, Apr 25, 2006 at 01:33:38PM -0500, Scott Marlowe wrote:
> On Tue, 2006-04-25 at 13:14, Bill Moran wrote:
> > I've been given the task of making some hardware recommendations for
> > the next round of server purchases.  The machines to be purchased
> > will be running FreeBSD & PostgreSQL.
> > 
> > Where I'm stuck is in deciding whether we want to go with dual-core
> > pentiums with 2M cache, or with HT pentiums with 8M cache.
> 
> Given a choice between those two processors, I'd choose the AMD 64 x 2
> CPU.  It's a significantly better processor than either of the Intel
> choices.  And if you get the HT processor, you might as well turn of HT
> on a PostgreSQL machine.  I've yet to see it make postgresql run faster,
> but I've certainly seen HT make it run slower.

Actually, believe it or not, a coworker just saw HT double the
performance of pgbench on his desktop machine. Granted, not really a
representative test case, but it still blew my mind. This was with a
database that fit in his 1G of memory, and running windows XP. Both
cases were newly minted pgbench databases with a scale of 40. Testing
was 40 connections and 100 transactions. With HT he saw 47.6 TPS,
without it was 21.1.

I actually had IT build put w2k3 server on a HT box specifically so I
could do more testing.
-- 
Jim C. Nasby, Sr. Engineering Consultant      jnasby(at)pervasive(dot)com
Pervasive Software      http://pervasive.com    work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf       cell: 512-569-9461