which is best for money? best performance?
if i do get the HD 5850, i will more then likely crossfire it some time down the track. Also if i got the GTX 275, i will sli sometime down the track. But atm wats the best over all?
As performance "GTX260SLI>HD5850>GTX275" is good but 2 gtx260 are more expensive then 1 HD5850 and they consume a lot more.
And, yes. I would advise you also to buy HD5850because is the most powerful of them all except SLI, but you also will have DX11 and better power saving, meaning the electric bill will be smaller.
The power consumption ain't worth it when the gains are that small if you compare it to the HD5850.
The 58xx series is surely the better choice right now but is the energy / $$ saving thing is a red herring.
Twin GTX 260's will consume about 173 watts versus 85 watts according to Antec's PSU calculator.
If you have a job or a GF, that means that you prolly don't get to play more than 3 hours a weekday and 8 hours over the weekend....though individual's mileage will vary....let's say 20 hours a week average at peak load.
20 hours x (173-85) x $0.10 per kw * 4.3 weeks a month / (1,000 watts per kw * 0.85 efficiency) = $0.89 per month