Hello, i want to buy a new ATI 5750 card but i don't know will my PSU support it or not here is my PC specs :
foxconn katana gti (p55) motherboard
core i7 860
6GB ram Kingston
ISO 400 Power Supply 300W
1 TB Hard
20 inch screen
geforce 9400 gt 1GB
for more info about my psu http://www.amazon.com/ISO-400-Power-Supply-300W/dp/B003...
No, you can't...
Do not cheap out on PSU, that's the most important thing inside your PC.
get a trusted brand like corsair, antec, ocz, seasonic, pcp&c, silverstone with 500W minimum to run any single graphic card.