Overclocking greatly varies due to what hardware is being used and who is doing the overclocking. Always remember that no two pieces of hardware will perform the same, so our results will differ from what you might be able to get.
Using the ASUS P6T motherboard with BIOS v8004 we pushed the limits of our early revision processor to see what it could do. At stock settings the Intel Core i7 965 processor runs with a 133MHz baseclock that is multiplied by the CPU multiplier to get the CPU speed and by the QPI multiplier to get the QPI speed. The Intel Core i7 965 has a 24x multiplier that is used to reach the final core clock of 3.20GHz. As you can see above, the ASUS P6T Deluxe motherboard runs at 133.6MHz, so the overall clock frequency is 7Mhz higher than the processor is rated.
By not touching anything in the BIOS other than the CPU Voltage (Auto to 1.35V) we were able to reach 4GHz right off the bat! This is not bad at all and is nearly an 800MHz overclock for a few seconds worth of work.
With a little extra voltage to the processor and a boost of the QPI from 133MHz to 145MHz we were able to hit 4.2GHz. With the system running at 4.2GHz it wasn’t fully stable, but we feel certain that with a little more effort that 4.2GHz should be easily had on most enthusiast motherboards. The Intel Core i7 series can overclock over 1GHz, which is a great sign for a brand new architecture!