I purchased a Dell Dimension E510 about two years ago and I am looking to upgrade it. It has a 3.2 Pentium D processor, 2 GB of memory, a 250 GB hard drive, Radeon X600 video card and I believe a 305w power supply. I'm looking to upgrade the memory and graphics card for gaming purposes and I want to know what the best graphics card I could get would be without risking the psu. Thanks.