my FF800 camme with a FW400 cable- My MacPro only has FW800 ports

SHOULD I be using a FW 800 cable and the FW 800 ports on the FF800 and MacPro?

I noticed in one of the tutorials, the person mentioned he's hooked his interface up to FW800... but no mention if it was using a 400x800 cable, or 800x800