I have acquired an old Dell Optiplex with a 300-watt psu. Current processor is Pentium D 945 (95-watt), single hard drive, single case fan, no add-on cards. I have XP installed as OS, 2GB DDR3 ram. The question is, will the psu be able to supply a GTX 750 at full draw? Current graphics card is 8400GS, but it honestly sucks. Thanks