Oh, and I forgot to add, the really interesting Sempron is the 3100 model which is a socket 754 version with on-board memory controller. Totally different design than the slower Semprons which are Athlon XP based. The 3100 is based on the Athlon 64, but without the 64 bit support enabled. Something to think about for the right price!
Scout
700 Mflops in SETI!