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Date: Fri, 9 Dec 2005 09:47:18 -0600
From: Frank Wiles <frank@wiles.org>
To: "Dave Page" <dpage@vale-housing.co.uk>
Cc: vivek@khera.org, pgsql-performance@postgresql.org
Subject: Re: opinion on disk speed
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On Thu, 8 Dec 2005 17:03:27 -0000
"Dave Page" <dpage@vale-housing.co.uk> wrote:

> > -----Original Message-----
> > From: pgsql-performance-owner@postgresql.org 
> > [mailto:pgsql-performance-owner@postgresql.org] On Behalf Of 
> > Vivek Khera
>
> > I have a choice to make on a RAID enclosure:
> > 
> > 14x 36GB 15kRPM ultra 320 SCSI drives
> > 
> > OR
> > 
> > 12x 72GB 10kRPM ultra 320 SCSI drives
> > 
> > both would be configured into RAID 10 over two SCSI channels using
> > a megaraid 320-2x card.
>
> 15K drives (well, the Seagate Cheetah X15's that I have a lot of at
> least) can run very hot compared to the 10K's. Might be worth bearing
> (no pun intended) in mind.
> 
> Other than that, without knowing the full specs of the drives, you've
> got 2 extra spindles and a probably-lower-seek time if you go for the
> X15's so that would seem likely to be the faster option.

  I agree, the extra spindles and lower seek times are better if all
  you are concerned about is raw speed.  

  However, that has to be balanced, from an overall perspective, with
  the nice single point of ordering/contact/support/warranty of the
  one vendor. It's a tough call. 

 ---------------------------------
   Frank Wiles <frank@wiles.org>
   http://www.wiles.org
 ---------------------------------