I use my old desktop as sort of an HTPC now. AMD Phenom II X4 945, 6GB of 1333 DDR3, and a Nvidia 315. It only has a 250 watt power supply, and I was looking for a gpu upgrade that would fit this. If not, I can upgrade to a 550 watt and maybe replace the motherboard as well to an AM3+ so I can put this 8350 in there when I'm done. I took the optical drive out, and only three USB ports are required. I would like not to use any additional PCIe 6-pin or 8-pin power, since then I would have to get Molex-6-pin as well. I was thinking a 7750 or something like that, but will this work with just 250W of power?
http://support.gateway.com/s/desktop/2010/gateway/dx/dx4320/DX4320sp2.shtml
http://support.gateway.com/s/desktop/2010/gateway/dx/dx4320/DX4320sp2.shtml