The UBB is an EXTREMELY I/O dependant program - well over two thirds of the performance problems that people encounter involve the system being unable to get data to the UBB fast enough. (The other third is mainly lack of memory and CPU power)
For extremely high traffic, we generally advise people to switch to OpenTopic, as it can handle the traffic far better than UBB ever can. In extreme cases, it can be less expensive.
If you wish to continue to run UBB, that system will not be up to the job. I would probably advise at least a P3-800. The memory's fine. Ensure you're using SCSI disks - a RAID if possible.
This particular board is running on a P3-600 with half a gig of memory and a SCSI RAID. The server barely knows anything's here. I can't recall more than one instance when the load's been over .5. We get about half a million pageviews a month.
