We’ve built the biggest single computer we could to see what happens to beefy power supplies when they are faced with a legitimately massive power draw.
We call it Big Willy. It's built of 16 500GB Western Digital hard drives driven by an Adaptec 31605 SAS controller card and a further eight Raptors controlled by the Asus L1N64-SLI motherboard, which is home to two dual core FX-72 processors, 4GB of TEAM Xtreem RAM, an 8800GTX and an 8800GTS.
Unfortunately, thanks to a slightly flaky engineering sample motherboard, we couldn’t get SLI working, and so resorted to a beefy GTX and a smaller GTS that didn't block access to the precious SATA connectors. But the motherboard does let us use two processors, and their excessive power draw compensates for the lack of SLI: especially when you consider that traditional SMP processing has been sidelined in favor of dual and quad cores on a single processor.
By the time we were done, there were no more motherboard connections. We couldn’t connect anything else to one computer, so we’re considering this the ultimate power requirement saturation point. Run HD Tach, 3D Mark 06 and Orthos SuperPi simultaneously, and you have to ask the PSUs on the market today one question: can you power Big Willy? Well can you, punk?