You think your expensive, custom-built gaming PC is powerful? You think you've got the hottest computer on the block because you can run Crysis at full specs? I'm not impressed. You want to see an impressive computer? Say hello to the Cray XT Jaguar supercomputer.
It's got some pretty mind-blowing specs: 45,000 quad-core Opteron processors, 362TB of RAM, and a 10PB (petabyte) storage array. The whole thing cooks along at a serious 1.64 petaflops. It's the fastest machine on earth being used for non-classified research, but you've got to assume there are even bigger and badder machines in the deep, secret halls of government.