I have the e2180 in my ASUS P5K SE (P35). Had it overclocked to 3.3GHZ in less then 5 minutes. It will boot at 3.8 but it starts to get hot at 3.8. I am using the stock heatsink.
Like another poster said; theres no reason not to overclock it. I never overclocked ever before and it was a breeze. If you dont want to change the BIOS just grab the ASUS P5K SE and use the Overclock utility to cange the FSB to 330 and the PCI to 100 while leaving the other settingsa on auto. Put the VCORE to 1.425 in the bios first to reach 3.3.
OOOOPS forgot to mention this thing is FAAAAAAAAAASSSSSSSSTT!!!!!!!! Real big difference from stock to 3.3.
At 3.3 it scores 5.7 in vista index while my $50 2gigs of ram scores 5.9
2770 cpu score in 3dmark06.
I can play Crysis on medium with my crappy 8500gt. Cant wait til I get my 8800.