Quad processor options

Hi,

I am curious if there are any real life production quad processor setups
running postgresql out there. Since postgresql lacks a proper
replication/cluster solution, we have to buy a bigger machine.

Right now we are running on a dual 2.4 Xeon, 3 GB Ram and U160 SCSI
hardware-raid 10.

Has anyone experiences with quad Xeon or quad Opteron setups? I am
looking at the appropriate boards from Tyan, which would be the only
option for us to buy such a beast. The 30k+ setups from Dell etc. don't
fit our budget.

I am thinking of the following:

Quad processor (xeon or opteron)
5 x SCSI 15K RPM for Raid 10 + spare drive
2 x IDE for system
ICP-Vortex battery backed U320 Hardware Raid
4-8 GB Ram

Would be nice to hear from you.

Regards,
Bjoern