Allan Campbell, Founder and Editor-in-Chief of KitGuru.com picked Noctua's award-winning NH-D14 cooler for his overclocking tests on Intel's latest Core i7 875K and Core i5 655K processors achieving a stunning speed of 4.8GHz ... setting a new world record for the K-series CPUs on air cooling.

This cooler is without a doubt my favourite on the market right now and I have achieved results very similar to good water cooling., says Allan Campbell. It is a brute for sure but the results are unmatched on air and it has a place in my heart now for every serious build I create.

Noctua's NH-D14 cooler has won more than 150 awards and recommendations from the international press since its introduction last November and has been chosen by first-tier websites such as Tom's Hardware for their overclocking tests on Intel's new K-series CPUs. As KitGuru's tests have shown, the NH-D14 can help to overclock Core i5 and Core i7 CPUs to speeds previously thought impossible on air cooling.

In order to achieve these outstanding results, KitGuru increased the CPU core voltage to 1.42V on the 875K and 1.46V on the 655K. Despite the enormous thermal overhead at such high voltages and 4.8GHz, the NH-D14 managed to keep the processors rock stable at load temperatures of 87 and 79 degrees Celsius respectively. KitGuru even reached the 5GHz barrier on the 655K but the system didn't prove entirely stable at this speed. As Allan notes, this is a staggering result and it shows just how capable the Noctua cooler really is.