I'm thinking about purchasing a new CPU but I'm not sure if I should upgrade my motherboard to get a CPU from the i-series or if I should just stick with a core 2 quad. I'm planning on spending $300 or less. My computer specs are a 750i nforce motherboard designed for an intel socket 775 FSB support 1333Mhz, nvidia gtx 275, core 2 duo e7400, 8gb ram, Windows 7 64bit. Thanks for the help.