i decided to get a new vga but the problem is that my power supply is a green450watt with one 12v *16amps rail,so here is the question:
can i get a 8800gt or 9600gt or i have to change the psu first??
From what I understand a single 9600gt requires 26A on the 12V line and the 8800gt burns more energy as well. You need to upgrade your psu first. get a good psu with ~30A on the 12V line it will be more than enough for your needs.
grackus, your enermax has plenty of juice for the 8800gt. i have the 400watt liberty and an 8800gt and works flawlessly. the combined 12v rails give you 32a (see picture on side of psu) while i have 30a with my 400watt. you only need 26a. enermax makes real nice psu's.