Intel's QX9770 is the one, currently available, quadcore CPU running with the highest default clock. We checked Intel's flagship and compared it with other processors.
Intel Core 2 Extreme QX9770
The QX9770 is running at 3,2 gigahertz and uses a 400 megahertz front-side bus. According to Intel this feature is not officially available until the X48 chipset, although boards using the P965 chipset, can reach this clock speed if overclocked. More of the CPU's basic data: 2x 6 MiByte Level 2 cache, SSE 4.1 support and - common among Intel's Extreme editions - an unlocked multiplier.
For our benchmarks we used Cinebench R10, the CPU score of 3DMark06, World in Conflict and Anno 1701. All those applications stress the CPU, so the Yorkfield can demonstrate his capability.