Hello mr.jingles,
First of all sufficient amount of RAM is required. Otherwise the processing could go into swap and last tens and hundreds times slower. However, when RAM is more then enough it will not effect on the processing speed.
CPU speeds up overall processing. We recommend Intel 3930K processor for desktop solutions, or dual-Xeon workstation.
Another point is to use GPU to improve Build Geometry stage speed. We recommend to use GeForce GTX580 or GTX680 card.
Cluster and network processing is not supported at the moment.