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

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 on a 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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