I upgraded my P5E BIOS to 0903 and it seems that this BIOS has some improvements on over-clocking.Right now, I can over-clock my Q9450 a little further and get it to run stable at 3.45 GHz with no voltage change. The system became unstable when I increased the FSB frequency further. I am guessing that the bottleneck is the DDR2-800 memory I am using (G.SKILL F2-6400CL5D-4GBPQ) since at 3.45 GHz the memory runs nearly 10% over its stock frequency. Nevertheless, since I have 8GB of RAM, 3.45GHz is already a pretty impressive result.