Hello, I have a Dell Inspiron 530 system and I want to upgrade my graphics card from a Radeon HD 2400 Pro to a Dell recommended Radeon HD4650 pcie 1 gb HDMI card. SYSTEM SPECS: Windows 7 Pro, Intel Core Dual Quad CPU Q6600 @ 2.40GHz and 4 GB RAM, 462.4 GB Hard Drive. 4 PCI slots..2 used and 2 free. I don't do gaming often, I just want a better graphics card. My primary question is can the original PSU, (which I believe to be 300W), power the HD4650 adequately? Basically, I just want a plug and play card that will work with my system as is.