All currently sold Intel C2D processors are very good overclockers, this is no secret. The "new" Intel E6750 with 1333MHz FSB bus is supposed to be an especially good processor to play with and reach at very high speeds, nearly 4GHz! If that sounds impossible, read on...

With an air cooled solution, we managed to get an impressive 3.80GHz, which however wasn't very stable. The problem was not the CPU itself but the cooling system. The processor was reaching very high temperatures resulting in not proper operation. So we had to lower the FSB and memory voltage:

3.760 was very good, the system appeared rock solid. However, we noticed an abonrmal behaviour:

The temperatures were above 80° C resulting in an automatic reduction in CPU speed in order to avoid burning the processor. According to the specifications for an Intel Core2 Duo Desktop Processor E6750, the thermal specifiaction temperature is given as 72° C.

Finally, we managed to get a 100% stable system at 3.720GHz (465x8), with 70° C maximum temperature:

What impressed us is that the CPU cools down very quick, so in idle mode we have very low temperatures:

All overclocking tests were done with the following system and BIOS settings:

• CPU Cooler: Arctic Cooling Freezer 7
• Motherboard: Asus P5B Premium VISTA Edition BIOS 0705
• Memory: 2x1GB Crucial PC-8000 (930Hz @ 5-5-5-15, Divider 1:1, 2.10V)
• VGA: MSI 7600GT Silent with Nvidia 93.71 installed
• HDD: WD 80GB SATAI (primary)
• HDD: Seagate 80GB SATAII (secondary)
• Operating system: Windows XP SP2 with all latest updates installed

Asus P5B Premium BIOS settings

• FSB: 465
• PCI-E: 100
• PCI Clock: 33MHz
• Spread Spectrum: Disabled
• Memory Voltage: 2.10V (this depends on your memory)
• CPU Core: 1.4875V
• FSB Termination: 1.45V
• NB Core: 1.65V
• SB Core: 1.80V
• ICH Chipset Voltage: 1.215V

And finally, here are several test results after overclocking the Intel E6750 up to 3.72GHz. As you will notice, the performance improvement is... significant!