Noctua NH-P1 – First impression with some preliminary testing

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.

Key features of the cooler

The design of this cooler is very different from conventional coolers, due to its design for passive and semi-passive use cases. Noctua NH-P1 is based on about thirteen thick aluminum fins, each with one millimeter thickness. A total of six copper heatpipes pass through these fins, ending in a large base. The fins themselves are perforated with rectangular holes for better heat dissipation to the surroundings, for the same reason there are also wide gaps between the individual fins.

In addition, the cooler is asymmetrically shaped so that it does not collide with the PCI Express slot closest to the processor. And due to the considerable imbalance of the cooler in regard to the central axis, I used the help of a passing-by stormtrooper (which, however, is not part of the cooler’s accessories!), for the needs of photo documentation.

The packaging of this cooler is plentiful. In addition to mounting kits for Intel and AMD sockets, you will also find a cloth for cleaning the processor and cooler from paste leftovers. The included thermal paste is the latest Noctua NT-H2 (finally!). Perhaps it’s a pity that there is only one set of clips for mounting the fan, but on the other hand, this cooler is designed primarily for passive use and the presence of two fans would only disproportionately increase its already large dimensions. I also recommend paying increased attention to the user manual, where you will find a clear diagram of how to optimally install the cooler and how and where to possibly mount a fan.

Of course, the proven and user-friendly SecuFirm2 mounting system has been preserved here, only instead of the traditional Phillips head it now uses TORX head screws. I asked a Noctua representative about the reason for this change, and whether the presence of TORX head screws can be expected in other Noctua coolers as well. The answer was that the TORX head wears less due to the larger contact area of the groove and the tip of the screwdriver. If there is sufficient demand and positive feedback, then we can really expect TORX head screws instead of Phillips head for upcoming coolers as well, although it will probably be reserved only for the top tier coolers and not the entire range of Noctua offerings.

Installation and mounting the cooler is a bit more complicated here due to the dimensions and disbalance of the cooler to the center axis of the base, but the whole process is quite fast and you should not encounter any difficulties.

Specs of the cooler and fan

I’ve compared the NH-P1 with two other high-end coolers from Noctua. It is quite nice to see that although the NH-P1 looks like a giant at first glance, the NH-D15 is even bigger and heavier with the fans installed. Of course, if you install a fan on the NH-P1, its overall dimensions will further increase.

It’s a bit more complicated with the maximum height of RAM modules. For the NH-P1 and NH-U12A, it depends on the socket, where the restriction only applies to the LGA 20xx socket and the DIMM slots to the left of the socket. With the NH-D15, the situation is even more complicated and the maximum supported RAM module height depends on the presence and type of fan that is installed on the front tower of the cooler.

The newly introduced NF-A12x25 LS-PWM cooler has a reduced maximum rpm compared to the original NF-A12x25 version > The newly introduced NF-A12x25 LS-PWM fan has its maximum RPM reduced, compared to the original NF-A12x25 version, which of course reduces the maximum air flow and maximum static pressure. However, these parameters are not very significant for the NH-P1 with large gaps between the fins. This fan also offers semi-passive operation, the rotor stops when the PWM signal drops below 20%. And the main advantage of this fan is the extremely low noise level, which is usually the number one priority in passive and semi-passive setups.

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.

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 results

Noctua NH-P1 scales beautifully with the fan speed, so it can be seen that its design does not put excessive resistance to airflow. Furthermore, it is nice to see that the fan in the side position provides better results in cooling efficiency. In addition, the noise of the Noctua NF-A12x25 LS-PWM fan in combination with the NH-P1 cooler is extremely low even at maximum speed. On request, I’ve added the results with the NF-A15 PWM fan in the upper position with the air flowing through the cooler (push). In addition, thanks to its atypical shape, this fan can be attached to this cooler using the included clips.

Perceive the value 33.0 dBA at 0 RPM only as the ambient noise level, in the fully passive mode the cooler is of course completely inaudible.

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.

Summary and conclusion

As I mentioned above, this article cannot be taken as an in-depth review, but rather as first impression and preliminary testing. I plan to publish another article about this cooler later, where I will focus on the efficiency of the cooler according to various configurations of air flow inside the model PC case.

Anyway, Noctua NH-P1 is a very interesting piece of hardware. Even in the fully passive mode, it manages to efficiently dissipate waste heat corresponding to today’s mid-range processors. The addition of the new NF-A12x25 LS-PWM fan will even further increase its efficiency without dramatically increasing the noise.

Even at maximum speed, this fan is very quiet and it offers the possibility of semi-passive operation if the PWM signal drops below 20%. Thus it’s an ideal combination for all enthusiasts of extremely quiet setups, which is further supported by the surprisingly acceptable dimensions of this cooler. It shouldn’t present a major obstacle to compatibility with conventional ATX cases.

But before you buy this cooler, I really recommend that you thoroughly get familiar with tips for passively cooled computer setups, and also visit the Noctua website for compatibility lists forprocessors, motherboards and PC cases. The only flaw of this cooler is its price, however it’s also a rather niche product for a very specific use case. Moreover, there is basically no real alternative to this cooler on the market.

• Contents
• Key features
• Test methodology
• Test results
• Summary and conclusion