Well, in fact I did not used the PC to record the Video , i tried in the beginning but even with my P4 3Ghz it wasn't enough fast, so i plugged the video out on my DVD recorder and then i converted it to divx.
The PC I used is a divx box with a P4 3Ghz, Ram: 1,5Gb and the graphic card is a very old ATI all in wonder 128 PRO.