xlinknz: ie using a Hybrid adapter such as the Haupaugge HVR-900 or Avermedia Volar Hybrid ?
And if so what spec CPU ?
You don't need a very high spec PC for doing this. The main issue is that because it's not using onboard MPEG2 encoding you can typically only use the software provided with the card and can't use software such as MCE, GB-PVR or Media Portal. There are some hacks available but the quality typically isn't anywhere near as good as a card with onboard MPEG2 encoding.