> -----Original Message-----
> From: Greg Stark [mailto:gsstark@mit.edu]
> Sent: Monday, April 18, 2005 9:59 AM
> To: William Yu
> Cc: pgsql-performance@postgresql.org
> Subject: Re: [PERFORM] How to improve db performance with $7K?
>
> William Yu <wyu@talisys.com> writes:
>
> > Using the above prices for a fixed budget for RAID-10, you
> > could get:
> >
> > SATA 7200 -- 680MB per $1000
> > SATA 10K -- 200MB per $1000
> > SCSI 10K -- 125MB per $1000
>
> What a lot of these analyses miss is that cheaper == faster
> because cheaper means you can buy more spindles for the same
> price. I'm assuming you picked equal sized drives to compare
> so that 200MB/$1000 for SATA is almost twice as many spindles
> as the 125MB/$1000. That means it would have almost double
> the bandwidth. And the 7200 RPM case would have more than 5x
> the bandwidth.
> [...]
Hmm...so you're saying that at some point, quantity beats quality?
That's an interesting point. However, it presumes that you can
actually distribute your data over a larger number of drives. If
you have a db with a bottleneck of one or two very large tables,
the extra spindles won't help unless you break up the tables and
glue them together with query magic. But it's still a point to
consider.
__
David B. Held
Software Engineer/Array Services Group
200 14th Ave. East, Sartell, MN 56377
320.534.3637 320.253.7800 800.752.8129
