Harith Aslam said:
im buiding a PC and havent actually got the PSU, so i dont know the model:(
That's a problem, if you can't even remember what you bought, then it's probably generic and won't power a $150 graphics card.
A cheepo 450w psu likely only puts out about 300 real watts, and that's not enough to power much.
So I need to know the make and model of the psu before I can recommend a graphics card.