Well that didnt take long just checked Xbit Labs data base and a 7300GS uses about 17Amps teh 7600GT uses about 36 Amps and a 3850 uses 60 odd Amps. Didnt write the exact figures down but its clear it does use more power. You had me worried there rangers
The 3850 will be the better of the two, it has H.264/VC-1 hardware decoding too. The only bad thing is sometimes, in my case anyways I have to have Catalyst 8.4 for DXVA to be working. The new Catalyst 9.4 drivers don't work for AGP cards that need DXVA.