Vivek,
> Dual Xeon 64bit with built-in 6-disk RAID10 or RAID5 (LSI RAID card)
> Dual Opteron 64bit with built-in 6-disk RAID10 or RAID5 (LSI RAID card)
> Dual Opteron 64bit with external RAID via fibre channel (eg, nstor)
Opteron over Xeon, no question. Not only are the Opterons
real-world-faster, they are less severely affected by the CS bug.
> I'm sure any of these will whip the bottom off the Dell 2650, but
> which will be the fastest overall? No way to know without spending
> lots of money to test. :-(
The SAN is going to be faster with a good SAN. That being said, I understand
that "a good SAN" is something like a $30,000 NetApp; the less expensive
SANs/NASes don't seem to be more than an external drive enclosure with a raid
chip (e.g. Apple XRaid). But we saw even a less expensive/slower EMC
machine improve performance just moving the pg_xlog off of the local PERC
RAID 5 and onto the SAN. So this is probably a good way to go if you can
afford it.
--
Josh Berkus
Aglio Database Solutions
San Francisco