Re: Quad processor options - Mailing list pgsql-performance

From J. Andrew Rogers
Subject Re: Quad processor options
Date
Msg-id 1084314209.4100.45.camel@localhost.localdomain
Whole thread Raw
In response to Quad processor options  (Bjoern Metzdorf <bm@turtle-entertainment.de>)
List pgsql-performance
On Tue, 2004-05-11 at 12:06, Bjoern Metzdorf wrote:
> Has anyone experiences with quad Xeon or quad Opteron setups? I am
> looking at the appropriate boards from Tyan, which would be the only
> option for us to buy such a beast. The 30k+ setups from Dell etc. don't
> fit our budget.
>
> I am thinking of the following:
>
> Quad processor (xeon or opteron)
> 5 x SCSI 15K RPM for Raid 10 + spare drive
> 2 x IDE for system
> ICP-Vortex battery backed U320 Hardware Raid
> 4-8 GB Ram


Just to add my two cents to the fray:

We use dual Opterons around here and prefer them to the Xeons for
database servers.  As others have pointed out, the Opteron systems will
scale well to more than two processors unlike the Xeon.  I know a couple
people with quad Opterons and it apparently scales very nicely, unlike
quad Xeons which don't give you much more.  On some supercomputing
hardware lists I'm on, they seem to be of the opinion that the current
Opteron fabric won't really show saturation until you have 6-8 CPUs
connected to it.

Like the other folks said, skip the 15k drives.  Those will only give
you a marginal improvement for an integer factor price increase over 10k
drives.  Instead spend your money on a nice RAID controller with a fat
cache and a backup battery, and maybe some extra spindles for your
array.  I personally like the LSI MegaRAID 320-2, which I always max out
to 256Mb of cache RAM and the required battery.  A maxed out LSI 320-2
should set you back <$1k.  Properly configured, you will notice large
improvements in the performance of your disk subsystem, especially if
you have a lot of writing going on.

I would recommend getting the Opterons, and spending the relatively
modest amount of money to get nice RAID controller with a large
write-back cache while sticking with 10k drives.

Depending on precisely how you configure it, this should cost you no
more than $10-12k.  We just built a very similar configuration, but with
dual Opterons on an HDAMA motherboard rather than a quad Tyan, and it
cost <$6k inclusive of everything.  Add the money for 4 of the 8xx
processors and the Tyan quad motherboard, and the sum comes out to a
very reasonable number for what you are getting.


j. andrew rogers




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