Opteron 144 on the ASRock 939Dual SATA2. Only issue I have is lack of Linux drivers for the ULi chips. An annoyance that can be worked around by compiling in the appropriate modules available from the ULi website. The Opteron is stable and speedy at 2.6 GHz though!! Linux throttles it down to about 1.5 GHz when idle to save power, and then when something requiring CPU horsepower starts, it cranks up to the full 2.6 GHz to meet the demand. Keeps things nice and cool with two 120mm case fans and the stock HSF.