I have a Gateway GT5228 and I need to find a new PSU that will run a Geforce 7600 GTS. I have a 300 Watt now that is running an AMD 4200 X2 2048MB DDR2 a 250GB SATA DVD Drive and a Geforce 6600 PCI-E card(I put it in a month ago to replace craptacular 6100). Will my 300 watt PSU be able to run a 7600? If not what is a cheap upgrade that will run it and that will fit my form factor. I have heard that Gateway uses a special connector that connects to the motherboard that will prevent me from using a non OEM PSU. Is this true? I dont care if upgrading voids my warrenty.
Sorry to be ther bearer of bad news here but a new PSU isn't going to work. Gateyaw PCs us propriatary parts. Meaning the motherboard and PSU are of there own design. SO they are not compatible with standard ATX motherboards and PSUs. Though the power connectors look the same it isn't. You will end up destroying the motherboard with a new PSU. Your best option would be to buy a new motherboard and a PSU. Though it seams this will be out side your budget.
That simply isn't true. I personally own a gateway, and installed a new 500W power supply in it. I even emailed gateway tech support, and they gave the power supply i bought the O.K.
To answer the original posters question, the 300W power supply you have should work pretty nicely with the 7600GT, as long as you don't have lots of other peripherals connected. Some 7600GT cards (the PNY one i think?) only recommend 300W anyways, so you should be fine.
You should not need to upgrade your supply as it is actually has closer to 400 w of rated output plus an additional 200 w 12 v rail for your add on video card. I'm running an OC 7900 GS on the same machine and have no problems. Good luck.
A 7800gt may run, but I wouldn't risk it. Theres a good chance it would work fine, but also a reasonable chance that it would harm components of your PC. I wouldn't go higher than a 7600gt with a 300W power supply, but it is your choice.