Some people have tried to upgrade their 8500, but there has been issues with the graphics card. Dell motherboards doesn't support all the graphics cards out there like other boards. You are also very limited by your dell power supply. I say a 750ti (EVGA: http://www.newegg.com/Product/Product.aspx?Item=N82E16814487024) would be a good upgrade for your machine. Physically this card will fit in your case and the power draw of this card is fine. It won't even need a 6 or 8 pin PCIe power cable.