Subject: Re: getting count for a specific querry
From: Scott Marlowe <smarlowe@g2switchworks.com>
To: Vivek Khera <vivek@khera.org>
Cc: pgsql-sql@postgresql.org
In-Reply-To: <8ef5bfe4806dac39bab8e07837dbab38@khera.org>
References: <003b01c53c70$6ff184b0$797ba8c0@jfradkin>
	<cb3b9f9319ae75a9f8eb756ff38e85e8@khera.org>
	<762e5c05040813354436bd27@mail.gmail.com>
	<8ef5bfe4806dac39bab8e07837dbab38@khera.org>
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Date: Fri, 08 Apr 2005 15:50:54 -0500

On Fri, 2005-04-08 at 15:41, Vivek Khera wrote:
> On Apr 8, 2005, at 4:35 PM, Bob Henkel wrote:
> 
> > desktop SATA drive with no RAID? I'm by any means as knowledgeable 
> > about I/O
> > setup as many of you are but my 2 cents wonders if the Dell RAID is 
> > really
> > that much slower than a competitively priced/speced alternative? Would
> > Joel's problems just fade away if he wasn't using a Dell RAID?
> >
> 
> "Dell RAID" is not one thing.  They sell "altered" RAID cards from 
> Adaptec and LSI.  Whatever alteration they do to them tends to make 
> them run not so fast.
> 
> I have a Dell SATA RAID (adaptec based) on the office server and it is 
> OK, though not something I'd buy again.
> 
> I have various PERC 3 and PERC 4 RAID controllers on my servers (SCSI 
> based) and they suck under heavy I/O load.
> 
> I wonder why the name-brand LSI cards work so much faster... perhaps it 
> is the motherboard?  I don't know, and I don't care... :-)  For me, 
> high performance DB and Dell servers are mutually exclusive.

It would  be nice to be able to put a stock ami megaraid in one and see.

Do you run your 2650s with hyperthreading on?  I found that slowed mine
down under load, but we never had more than a couple dozen users hitting
the db at once, so we may well have had a different load profile than
what you're seeing.