Hi. I have sold my old motherboard, but now my friend is having issues. First, I was using the board with a Q8300, that I did't sold. I even overcloked it, from 2.5 to 3.3~ GHz, prime95 stable for days, etc... Now he is trying to use his Q9550, but the board when turned on says "Overcloking failed" etc etc, press F1 setup, or F2 defalt... We tried to set manually to 333/6x and voltages +150mV (I will explain it later) etc, the system starts up, but only with 2 cores, and as expected with 2.0Ghz. http://i.imgur.com/crcABHN.jpg "Overcloking failed" After that, when we try to change multiplier up, like 6.5, 7x, nothing happens, the system starts up with 2.0ghz, 6x, 2 cores... We notice that, after first power it on, and it says failed to overclock, the voltages was 1.1~V on vcore. That is why I said to him use more voltage on the configs... Now stays 1.225~1.25v I think. I think that voltage should be detected automatically, but I don't know why it doesn't work on auto... http://i.imgur.com/NQlFGVe.jpg After set vcore settings +150mV http://i.imgur.com/86gJQCJ.jpg Before set vcore settings, 1.1V~ The Asus website says that even with the oldest bios, the Q9550 should work. We also tried the last bios, nothing changed. Why it works with the Q8300, that is the same arch, Yorkfield, similar voltages, FSB etc, and the Q9550 don't work? We tested the Q9550 on other motherboard, it works. And why 2 cores? Its a safe mod config? He said that tried to reinstall Windows, nothing changed... I never had issues like that before. If anyone can explain, or say anything that helps to troubleshoot this issue, please report here Thank you.