movielord25 :
[I heard its pretty bad. I have a Raidmax power supply, so i'm I better off buying a new one right away?
They only Raidmax i could find is a Tier4 (under that i would recoment to avoid any PSU), not very advisable but still it will work and the power is enought to power the 750.
Anyway i would allways recomend to use proper a PSU, if you are already going to change the PSU, just wait till you get the new PSU and change then the GPU also.