Cooling Efficiency Tests

Using the weakest cooling system of our today’s testing participants we managed to overclock our quad-core processor almost to its maximum of 3950MHz without losing stability or getting into the throttling mode. The processor Vcore was increased to 1.5875V in the mainboard BIOS (1.55~1.57V according to the monitoring utility). The obtained results are summed up on the diagram below:

First of all I would like to point out that Noctua NH-C12P doesn’t depend on the rotation speed of its original fan that much: increasing its rotation speed from ~940RPM to ~1390RPM brought only 3ºC improvement in processor temperature in an open testbed and only 2ºC improvement in a closed system case. It indicates that they designed a very smart heatsink and selected a good fan for it. During our experiments with other fans, we managed to lower the processor temperature by 7ºC, but unfortunately, at the expense of uncomfortably high level of noise (when we replaced Noctua NF-P12 at ~940RPM with Scythe Ultra Kaze at ~2900RPM). By the way, even though Ultra Kaze has a pretty big “dead zone” Noctua NH-C12P still demonstrated its maximum efficiency with this particular fan.

As for the comparison between Noctua NH-C12P and Thermalright SI-128, the results are pretty predictable here. Larger heatpipes diameter and almost 58% bigger heatsink surface size do not leave our hero any chances to win. Thermalright SI-128 is 6-7ºC more efficient than Noctua NH-C12P with identical Scythe Ultra Kaze fan in its quiet mode at ~1010RPM. Moreover, Thermalright solution allows pushing the processor frequency even higher: to 4030MHz at 1.6V Vcore, while Noctua cannot cool the quad-core CPU at this speed any more. However, once we sped up the Noctua NH-C12P fan to its maximum rotation speed, we managed to continue successful CPU overclocking.

We didn’t include any acoustic tests this time for one very simple reason: we have already tested all the fans that are participating in our today’s test session. As for the Noctua NH-C12P with its original fan, I can say for sure that it is a very quiet cooler at ~940RPM and ~1070RPM, and at ~1390RPM it generated moderate noise. However, since the difference between these two modes is only 1-2ºC, I would strongly suggest using Noctua NH-C12P in one of the quiet modes depending on your sensitivity to noise.