PCs today can demand an unholy amount of power, and PSU's manly enough to do the job may require a second mortgage. For that reason exists the dual-PSU mod. The basic concept is that one PSU acts as a master, the other a slave. Both PSUs power a PC simultaneously (unlike redundant PSUs). This way, you can adequately power even the most monolithic rig with a couple of $20 PSUs! It's a fairly easy mod, too. The hardest part is housing two power supplies in one chassis.