A friend of mine wants to upgrade the GPU in a HP pavillion prebuilt computer. He only has a 300W stock power supply, but I have a Gigabyte GE-P450N-C2 (450W, max 550W) that I'm not using, and am capable of fitting to his machine.
The current GPU is a GT530, and he's looking for something along the lines of a 660Ti. My first question is will that power supply be adequate (SB i5 cpu, no OC) to run a GPU of that level, and if not, what is the best thing he can put in the machine. The secondary concern is size, as there is a limited card width due to the positioning of the WiFi card in the adjacent PCI slot, and I have had little luck getting that dimension from card manufacturers. Getting a more powerful PSU is pretty much out of the question, due to financial constraints. As far as I can tell, using that PSU would be relatively painless in terms of cabling, though it only has one 6+2 pin PCIE power connector, so a molex to PCIE conversion would be necessary (for a 660Ti).
In addition to the above points, I welcome any suggestions.
He would also prefer Nvidia, though I may be able to sway him to an AMD card if the benefits are enough.