X1950 1GB pro, worth it? I got a new PC and it has two 7600GS (512mb) in and its useless, it works better with 1 in than two, so I want to upgrade my video card, I have around 250£ - 300 £ (500-600$) to spend and I figure a X1950 Pro might be good, better than the nvidias cards? Oh and do I need a special motherboard as its GDDR4? Thanks Brock