Intel Sandy Bridge-E Overclocking Detailed

In mid-November, Intel is expected to launch its first desktop chips based on the high-performance Sandy Bridge-E architecture, which are expected to bring a boost in CPU power but also improved overclocking capabilities when compared to today's second generation Core processors.

From the information available at this point in time, Intel's initial lineup will be comprised of three processors, dubbed the Core i7-3820, i7-3930K, and i7-3960X.

We already detailed the specs of these CPUs in a series of previous articles, so we are not going to focus our attention on this aspect right now, but what's important to note is that the two latter chips come with an unlocked CPU multiplier, while the former lacks such a feature.

In the case of LGA 1155 processors, this would severely limit CPU overclocking, as the BCLK frequency can only be adjusted by less than 10% resulting in an unimpressive performance gain.

Fortunately, this isn't the case with Sandy Bridge-E, since these processors, outside of BCLK and CPU multipliers, have also introduced a feature called reference clock ratio (RCR).

This is a special multiplier that affects the CPU and memory frequency, but doesn't touch other things such as the SATA and USB buses like BCLK does.

What this basically means is that overclockers have more freedom in increasing the processor operating frequency without affecting the overall stability of the system.

According to BitTech, Intel will make available three such ratios in its upcoming Sandy Bridge-E processors, namely 1.00x, 1.25x and 1.66x.

In order to find out the settings they have to apply to reach a certain overclock, enthusiasts will have to go through quite a bit of math, but basically the final CPU multiplier and BCLK settings will be determined after dividing the targeted processor frequency to the clock ratio selected (a more detailed explanation is available on the AnandTech website).

As a conclusion, one can say that the new overclocking method used by Intel for Sandy Bridge-E is quite a bit more complicated than what we were used to see in Nehalem-based CPUs, although it would definitely make the ride more fun.

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