I am upgrading my Inspiron 570. It has an AMD Athlon II X2 245, 4gb of ddr3 ram, a Radeon HD 4650, a 300w PSU. I am looking to get this as a PSU and I was looking at a 6670 for a graphics card. I'm looking to play games like Borderlands, Just Cause 2, Fallout, and the such on High or so and last me a little while. I have a low budget but I have heard the 6670 can handle it. What is the difference between the gddr5 and the ddr3 versions? What about the HIS, XFX, and Sapphire? Do I need to just abandon the 6670 and go higher? Thanks