There is an opinion that increased nominal clock frequency of the new processor should result into a higher overclocking potential. It is often true, but things are totally different with Core i7-3970X. As we have already seen, this processor has been created by “legally” overclocking the previous CPU model and doesn’t have anything new in its semiconductor core. It uses the same exact stepping of the 23 nm core as Core i7-3960X, and its clock speed increased together with the TDP. In other words, Core i7-3970X should overclock in exactly the same manner as Core i7-3960X.
But in reality, this isn’t bad at all. Core i7-3960X overclocked well, and the same is true for Core i7-3970X. Both these processors belong to Extreme Edition series, which means that they have unlocked clock frequency multipliers, i.e. allow settings the clock frequency without changing the BCLK frequency. However, the LGA 2011 platform allows adjusting the clock generator frequency in the 100-125 MHz interval without any loss of system stability. So, overclockers have a lot of freedom to experiment. Nevertheless, it is not very good to change the BCLK frequency during Core i7-3970X overclocking: it won’t provide any additional performance boost, but will simply offer a different route to adjusting the CPU clock. Therefore, we chose to overclock our test processor by simply manipulating its clock frequency multiplier.
So, the goal of our experiments was to determine the frequency, at which Core i7-3970X would be able to continuously operate in 24/7 mode without losing stability. Therefore, we didn’t use any potentially dangerous voltage settings and worked with NZXT Havik 140 air-cooler. After that we tested our overclocked system stability by running OCCT 4.3.2 utility (30-minute test in Large Data Set mode).
Our Core i7-3970X remained stable at the maximum frequency of 4.6 GHz. The CPU Vcore in this case was set at 1.375 V and Load-Line Calibration function was enabled.
I have to say that maximum acceptable temperature for Core i7-3970X cores is the same as before - 91°C. After that the processor’s thermal throttling kicks in. therefore, it is important to choose a cooling system with proper efficiency and the use of more efficient systems may actually further improve the overclocking results. In our specific case, the temperatures were 5-10°C below the critical maximum at all times.
All obtained results indicate that Core i7-3970X overclocks the same way as its predecessor. We have already reached 4.6 GHz frequency before – this is typical overclocking level for any Sandy Bridge-E processors with C2 stepping under an efficient air-cooler. In other words, the new Intel processor doesn’t really offer anything new to overclockers in this respect.