The bigger question here is why this guy would need a PIII-s to run MythTV. The PVR150 is usually the standard capture card used in a MythTV build, and since it is a hardware capture card, the cpu is not important. A 700 MHz Coppermine is powerful enough to play back mpeg2. Hell a K6-2 can play mpeg2. Besides, all graphics chips from 2000 and newer have hardware mpeg2 decoding built in, meaning once again the cpu doesn't matter for mpeg2. The 700 MHz Coppermine is also fast enough for DivX/mpeg4. My friend's PII 450 is just barely fast enough to play DivX files, the Coppermine 700 is more than enough. Seriously, unless the Myth box will also be doing some transcoding, it doesn't need more than the 700 mHz Coppermine. Save your money.