On Nov 18, 2005, at 1:07 AM, Luke Lonergan wrote:
> A $1,000 system with one CPU and two SATA disks in a software RAID0
> will
> perform exactly the same as a $80,000 system with 8 dual core CPUs
> and the
> world's best SCSI RAID hardware on a large database for decision
> support
> (what the poster asked about).
Hahahahahahahahahahahahaha! Whooo... needed to fall out of my chair
laughing this morning.
I can tell you from direct personal experience that you're just plain
wrong.
I've had to move my primary DB server from a dual P3 1GHz with 4-disk
RAID10 SCSI, to Dual P3 2GHz with 14-disk RAID10 and faster drives,
to Dual Opteron 2GHz with 8-disk RAID10 and even faster disks to keep
up with my load on a 60+ GB database. The Dual opteron system has
just a little bit of extra capacity if I offload some of the
reporting operations to a replicated copy (via slony1). If I run all
the queries on the one DB it can't keep up.
One most telling point about the difference in speed is that the 14-
disk array system cannot keep up with the replication being generated
by the dual opteron, even when it is no doing any other queries of
its own. The I/O system just ain't fast enough.
