Less than 5 GHz is pathetic!
'Shark Team', an overclocking team hailing from Italy, broke a new overclocking record recently. They managed to push an E8600 to an incredible 6526 MHz.
A great help in this adventure seems to be the DFI DK P45-T2RS PLUS motherboard, which is, by many reports, capable of some fierce overclocking.
Shark Team used the following BIOS settings to achieve this craziness:
"CPU VID Special +650.0mV (1.968 ... not limit yet)
DRAM Voltage 2.56V /2.54 Actual
SB Core 1.555V
NB COre Voltage 1.42V
CPU VTT Voltage 1.38V
Dram Speed 1200 @ Boot
Strap To NB : 400
Boot @ 610 X 10 / 652.2 SetFsb"
In addition, the team used a BIOS volt-modification program ('Dark CoreMod'), and the CPU cooling was taken care of "KingBlock Rev 1.0" which is presumably, a custom built liquid nitrogen cooling solution. They also used a 'Special Edition' overclockers version of Windows XP made by some character who goes by the name of Hiwa.
While just about everything about this overclocking venture is impressive, perhaps the E8600 being even capable of hitting 6.5 GHz (or greater) is something worth drinking beer about.