AMD’s new 45nm processor the Phenom II looks to be set to take the on Intel again. While being demoed for the press they were able to overclock the quad-core processor to 5Ghz using dry ice. It had been leaked earlier that 4Ghz was possible using on air but no reports have officially come out on that. It was also reported that the chip hit 6Ghz using liquid nitrogen, which I don’t know about you but I don’t have an abundance of.
Source: PC Perspective