Re: Intel SRCS16 SATA raid? - Mailing list pgsql-performance

This is a different thread that the $7k server thread.
Greg Stark started it and wrote:

 "I'm also wondering about whether I'm better off with one of these
 SATA raid
 controllers or just going with SCSI drives."



Rick

pgsql-performance-owner@postgresql.org wrote on 04/15/2005 10:01:56 AM:

> The original thread was how much can I get for $7k
>
> You can't fit a 15k RPM SCSI solution into $7K ;)  Some of us are ona
budget!
>
> 10k RPM SATA drives give acceptable performance at a good price, thats
> really the point here.
>
> I have never really argued that SATA is going to match SCSI
> performance on multidrive arrays for IO/sec.  But it's all about the
> benjamins baby.  If I told my boss we need $25k for a database
> machine, he'd tell me that was impossible, and I have $5k to do it.
> If I tell him $7k - he will swallow that.  We don't _need_ the amazing
> performance of a 15k RPM drive config.  Our biggest hit is reads, so
> we can buy 3xSATA machines and load balance.  It's all about the
> application, and buying what is appropriate.  I don't buy a Corvette
> if all I need is a malibu.
>
> Alex Turner
> netEconomist
>
> On 4/15/05, Dave Held <dave.held@arrayservicesgrp.com> wrote:
> > > -----Original Message-----
> > > From: Alex Turner [mailto:armtuk@gmail.com]
> > > Sent: Thursday, April 14, 2005 6:15 PM
> > > To: Dave Held
> > > Cc: pgsql-performance@postgresql.org
> > > Subject: Re: [PERFORM] Intel SRCS16 SATA raid?
> > >
> > > Looking at the numbers, the raptor with TCQ enabled was close or
> > > beat the Atlas III 10k drive on most benchmarks.
> >
> > And I would be willing to bet that the Atlas 10k is not using the
> > same generation of technology as the Raptors.
> >
> > > Naturaly a 15k drive is going to be faster in many areas, but it
> > > is also much more expensive.  It was only 44% better on the server
> > > tests than the raptor with TCQ, but it costs nearly 300% more ($538
> > > cdw.com, $180 newegg.com).
> >
> > State that in terms of cars.  Would you be willing to pay 300% more
> > for a car that is 44% faster than your competitor's?  Of course you
> > would, because we all recognize that the cost of speed/performance
> > does not scale linearly.  Naturally, you buy the best speed that you
> > can afford, but when it comes to hard drives, the only major feature
> > whose price tends to scale anywhere close to linearly is capacity.
> >
> > > Note also that the 15k drive was the only drive that kept up with
> > > the raptor on raw transfer speed, which is going to matter for WAL.
> >
> > So get a Raptor for your WAL partition. ;)
> >
> > > [...]
> > > The Raptor drives can be had for as little as $180/ea, which is
> > > quite a good price point considering they can keep up with their
> > > SCSI 10k RPM counterparts on almost all tests with NCQ enabled
> > > (Note that 3ware controllers _don't_ support NCQ, although they
> > > claim their HBA based queueing is 95% as good as NCQ on the drive).
> >
> > Just keep in mind the points made by the Seagate article.  You're
> > buying much more than just performance for that $500+.  You're also
> > buying vibrational tolerance, high MTBF, better internal
> > environmental controls, and a pretty significant margin on seek time,
> > which is probably your most important feature for disks storing tables.
> > An interesting test would be to stick several drives in a cabinet and
> > graph how performance is affected at the different price points/
> > technologies/number of drives.
> >
> > __
> > David B. Held
> > Software Engineer/Array Services Group
> > 200 14th Ave. East,  Sartell, MN 56377
> > 320.534.3637 320.253.7800 800.752.8129
> >
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