If you’re in a buying mood, or just wanting to do some productive doodling, head over to Sun’s relatively recently added web page detailing Constellation reference designs. See what it takes to host systems at 70, 210, and 579 TFLOPS.
I love the moxie of the web pages; note the marketing language that informs you that yes you can scale Constellation “down to TeraFLOPS” …if you’re that sort of person (want a can of Pabst with that cluster buddy?).
Anyway, tip o’ the chapeau to Sun’s HPC Watercooler.