Intel’s latest CPU architecture, Sandy Bridge, has completely turned the overclocking scene on its head, while there are limitations on how you can overclock these new processors, the reports about the death of overcbcking with sandy Bridge are greatly exaggerated, in this guide, we’ll show you how to get the best out of you sandy Bridge processor, with both an unlocked ‘K’ type sandy Bridge processor and a locked version.
Sandy Bridge Overclockdng Basics
Simply put, to overclock a processor is to increase its clock speed above its specified frequency. Most desktop processors nowadays run from anything between 2.0GHz to 3.3GHz -the current crop of Sandy Bridge CPUs range from 2.8GHz to 3.4GHz.
This clock speed is derived from multiplying two numbers together the base clock (BCLK) and the CPU multiplier. For Instance, the BCLK on the Sandy Bridge platform is at 100MHz by default and the top Sandy Bridge CPU now, the Core i7-2600K has a default CPU multiplier of 34. Hence, the Core i7-2600K runs at 3400MHZ or 3.4GHZ.
Increasing either the BCLK or the CPU multiplier will raise the resultant clock speed. This is exactly what overclockers do, but Intel has thrown a curveball by designing the Sandy Bridge architecture such that it is not feasible to increase the BCLK significantly. On the average, we’re looking at a gain of around 5MHz to 7MHZ – 105.0 to 107.0 MHZ.
Intel is also offering two types of Sandy Bridge processors, the ‘K’ SKU (with the ‘K’ suffix) and those without. The critical difference is that the ‘K’ processors have unlocked multipliers — you can increase the default CPU multiplier (up to 60 on some models). On a non-K processor, you can only decrease this multiplier.
In short, it’s much easier to increase the CPU multiplier on a Sandy Bridge processor, which means that you should get a ‘K’ processor if you intend to overclock. There are currently two ‘K’ models available, the Core i7-2600K and the Core i7-2500K.
Anatomy of the Overclocking BIOS
The ASUS Maxim US IV Extreme (Intel P67) motherboard is used to explain the BIOS settings that need to be adjusted when overclocking. Most motherboards will have similar settings; refer to your manual for more details.
The 5 Steps of Overclocking
1. Boot into BIOS and increment the CPU multiplier or BCLK.
2. Save the new settings and reboot to Windows.
3. Check the clock speed using CPU-Z (www.cpuid.com). You need to load the system by starting an application to get an accurate reading.
4. Run an intensive benchmark like Primers for around an hour to verify system stability.
5. If the system is stable, restart to Bios and continue increasing the clock speed. Else, restart to BIOS and try to increase the Vcore rating. Rinse and repeat.