Test methodology
It’s been a long time since we’ve seen the prototype, but the first passive cooler from Noctua with the designation NH-P1 was finally introduced this week. Its design is rather different from usual coolers as the main priority is maximization of heat dissipation to its surroundings. And to increase its efficiency, a new A12x25 LS-PWM fan with very quiet operation was also introduced as complementary accessory for semi-passive cooling.
Test methodology
This text does not aim at in-depth analysis, that will be the subject of another article to be published later. In addition, our usual methodology cannot be used for passive and semi-passive coolers. For these reasons, I had to adjust the conditions of the stress tests. But as a heat generator, I still used the Intel Core i7-5820K processor in the ASRock X99 Taichi motherboard.
I left the whole setup on the Streacom BC1 benchtable without fans that would provide airflow. The stress tests were performed as usual using the Aida64 Extreme application with a duration of 45–60 minutes. For obvious reasons, I only tested the cooler on the base clock of the processor without overclocking. At the same time, however, I expanded the range of tests by more speed levels. So I first tested the Noctua NH-P1 cooler in passive mode, followed by two sets with the added NF-A12x25 LS-PWM fan at four speed levels (300, 600, 900 and 1,200).
In the first set, the fan was placed on top of the cooler and the air flow was directed upwards. In the second set, I then placed the fan on the side of the cooler so that air could flow from the PCI Express slot through the fins toward the top edge of the motherboard. The CPU power consumption during these tests was 85–90 watts, a similar value to current mid-range processors.
At the end of the test, the highest temperature reached was always read. I got all the data regarding temperatures and energy consumption of the processor from the application HWiNFO64. The measured values were then corrected against the room temperature as the resulting Delta T value. The noise level was measured using a calibrated sound level meter Voltcraft SL-100 at a distance of 50 cm from the cooler.