Now this is something that will take quite a few people by surprise. Intel is now adding overclocking features to its boards - and not just little tweaks - there is quite a bit of grunt under the hood.
Intel hasn't jumped on the automatic overclocking bandwagon like ASUS, MSI and Gigabyte but they have included a few tweaks. To access the overclocking features you need to enter the BIOS, go to the advanced top menu and select the Chipset Configuration sub menu. Once there you will see the Default Setting Override option. Once in there you are faced with the Intel overclocking setup. Intel has a lot of writing up in this screen warning you that altering the frequencies and voltages will void your CPU and motherboard warranties as well as possibly affect system stability. You need to say you accept this and the overclocking options are then selectable.
When running a Pentium Extreme Edition CPU your first option is Processor Ratio Multiplier. You can adjust this from the default minimum of 13x up to a maximum of 60x.
Next option on the list is the Processor CPU VID. This allows you to change the processor voltage from 1.3v (default for Presler or 1.38v for Smithfield) up to a maximum of 1.6v in 0.025v increments.
Next we have the Host Frequency Override which allows you to select different FSB settings. Intel does limit the amount of FSB you can choose unfortunately; there are four options only: 533, 800, 1066 and 1333MHz. You then are given the option to boost the PCI, PCI-E frequencies - leaving them at default locks them to 100MHz for PCI-E and 33MHz for PCI.
The last two voltages in this setting are MCH voltage override and Front Side Bus voltage override. This allows you to stabilise the FSB and the MCH to ICH links when overclocking. Ranges for both are 1.2v up to 1.4v in 0.1v increments.
To overclock the DDR2 you need to exit this menu and locate the Memory Configuration sub menu in the advanced top menu. Here you can adjust the DDR-2 memory speed to 333MHz, 400MHz, 533MHz, 667MHz or 800MHz. DDR2 voltage control is also located here with settings from 1.8v up to 2.2v.
With these options we did a two stage overclock of the CPU. First we lowered the multiplier back to 13x and raised the FSB to 1333MHz to see if the board would post. It did, but refused to run Windows at this speed, no matter how much voltage tweaking we did.
Next we did a multiplier overclock to see how far the CPU would go. We raised the multiplier from its default of 13x (266MHz x 13 = 3458MHz) and went up each multiplier till we hit a wall. In air we managed to get to 15x, which gave us 3.9GHz. We then stuck our Gigabyte 3D water cooler onto the unit to see what we would get. With this we got to 16x which gave us a very impressive clock speed of 4.2GHz - which is about a 800MHz overclock past the default speed, on a reference motherboard! We did encounter a few stability problems relating to our test PSU; however, given the right conditions, this CPU manages to pull some serious clocks and should go a long way to making Intel's latest CPU and the 975X chipset a true gamers option, especially given official ATI Crossfire support.