The Tyan Typhoon 600 series provides 256 gigaflops in a single machine (see Tyan Typhoon 600 series reaches 256 gigaflops for "personal supercomputing"). From the Engadget piece:

Well, we've just laid our eyes on the Typhoon 600 series, which is loaded to the brim with Clovertown chips, reaching 256 gigaflops worth of processing power from a single outlet. Of course, the Typhoon isn't exactly going to crack the Top500 list of supercomputers, but it'll probably work much better than that those decked out quad-core getups we've seen thus far.