I would suggest getting another 5xxx series motherboard. The 5xxx and 6xxx series have enough case differences that the motherboards aren't universal. As a general rule the motherboards for the 62xx and 63xx are interchangeable. Anything on the 5xxx is interchangeable and the 6400-6500 motherboards are all interchangeable. But don't go out and purchase a 6xxx motherboard unless you are absolutly sure about compatibility.