Bear in mind server OSes may also be a bit diff to load than workstation OSes, depending on what you are loading.
But fast SCSI drives (often in a RAID confuguration for data integrity) in combination with a good fast CPU with lots of L2 cache, a good server board for good internal bandwidth, and loads of error checking RAM will help speed up processing taks quite a bit.
But you pay for it.

That's why servers are more expensive.
Cheers
Mick