Supported CPUs:
Intel Xeon E5450/ 3.00 GHz, 12MB L2, 1333 MHz, FSB, 80W GX574AA
Intel Xeon E5440/ 2.83 GHz, 12MB L2, 1333 MHz, FSB, 80W GX573AA
Not Supported:
Intel® Xeon® Processor X5460 - this is a 120 Watt TDP (Thermal Power Design) model. The motherboard does not support CPUs with that kind of TDP.