Lateral your 7900 video card is the same as mine four years ago. The 7900 card will not run ROF. I can tell you that the newer cards like my 4600 need a larger computer case and the card is powered by two plugs instead of one like the 7900 series.
Lateral the power cord is the same type powering your 7900 and you should have a extra one coming off your power supply The 4600 series take up two slots on your mother board and is twice as big in size.