Cooler Comparison Testing
Cooler Testing Methods
To best gage the quality of the system coolers under review, system CPU temperature and cooling system audio measurements were taken with the CPU idle and under load. To replicate CPU idle conditions, the system was rebooted and allowed to sit idle for 10 minutes. To replicate a stress system load on the Z77-based system, a combination of LinX and FurMark were run over a 30 minute period with LinX running for 500 loops with Memory set to All and FurMark running at 1280×1024 resolution and 2x MSAA in stress test mode. For the Z87-based system testing, Aida64 System Stability Test was used in conjunction with FurMark for 30 minutes per run. After each run, the system was shut down and allowed to rest for 10 minutes to cool down. Then the CPU cooler was removed, cleaned, and remounted to the CPU with fresh thermal paste applied. This procedure was repeated a total of 12 times for each cooler – three times each for the stock and overclocking speed runs on the Z77 and Z87-based systems.
Temperature measurements were taken directly from the CPU thermistors using RealTemp (the newer Tech|Inferno edition). For the Z77-based systems, the highest recorded value for idle and load temperature were used for the run. Because of the volatile nature of the Haswell thermistor readings, the Z87-based system temperatures were measured in a different manner. For idle temperatures, the highest recorded value was used for the run. For load temperatures, a series of three values were notated: the average (high and low) across all cores, the average (high and low) across the single highest core, and the high temperature.
To adequately measure the Noctua NH-D15 CPU cooler performance, performance testing was done for all scenarios under three operational conditions – dual fan and dual fan with LNA (low-noise adapter). In dual fan mode, fans were directly connected to the PSU and run at full speed. In single fan with LNA mode, the included low-noise adapter were plugged in between the fans and the PSU power adapter. Noctua NF-A15 140mm fans were used for all test scenarios run.
Note that the temperature values are reported as deltas rather than absolute temperatures with the delta value reported calculated as CPU temperature – ambient temperature. For all tests, room ambient temperature was maintained between 23-27C. Sound measurements of the system cooler where taken with the sound meter placed 3 feet away from the system with all other devices in the room silenced. The Sound Meter Pro applet on a Samsung Galaxy S3 mobile phone was used to measure decibel level.
Intel Z77-based Ivy Bridge System Testing
CPU Stock Speed Testing
The CPU stock speed testing was conducted with the BIOS defaults set with Turbo Mode disabled, equating to a 3.4GHz CPU speed, 1600MHz memory speed, and 100MHz base clock. The Intel Speedstep functionality remained enabled for the duration of the testing to get realistic CPU idle performance conditions.
The Noctua NH-D15 has no problem cooling the Ivy Bridge processor at stock speed. In fact, the cooler's performance did not change even when running both of its fans with the LNA (low noise adapter) cables connected. Its performance was consistent or better than the other cooler's tested.
CPU Overclocked Speed Testing
The CPU overclocked speed testing was conducted with known stable settings from a previous board review with Turbo Mode disabled, equating to a 4.4GHz CPU speed, 1960MHz memory speed, and 105MHz base clock. Also, the CPU-integrated graphics processor was disabled to reduce the processor heat generation. The Intel Speedstep functionality remained enabled for the duration of the testing to get realistic CPU idle performance conditions.
Board voltage settings were configured as follows:
- CPU Core Voltage – 1.2750
- CPU I/O Voltage – 1.150
- DRAM Voltage – 1.6255
- System Agent Voltage(SA) – 1.0850
- CPU PLL Voltage – 1.7500
- PCH 1.05 – 1.0995
Again, we see the NH-D15 cooler perform well against the other coolers with virtually no difference in performance when using the fans at full speed versus with the LNA cables. The system remained fully stable during all tests run.
Intel Z87-based Haswell System Testing
CPU Stock Speed Testing
The CPU stock speed testing was conducted with the BIOS defaults set for the CPU (including enabling of the CPU-integrated graphics processor) and Turbo Mode disabled, equating to a 3.4GHz CPU speed, 1600MHz memory speed, and 100MHz base clock. The Intel Speedstep functionality remained enabled for the duration of the testing to get realistic CPU idle performance conditions.
The NH-D15's performance with the Haswell as stock settings mimics that of its Ivy Bridge performance. There is a minimal difference seen between running with stock fan configuration and with LNA cables attached.
CPU Overclocked Speed Testing
The CPU overclocked speed testing was conducted with known stable settings from a previous board review with Turbo Mode disabled, equating to a 4.68GHz CPU speed, 1780MHz memory speed, 4.0GHZ ring bus speed, and 167MHz base clock. Also, the CPU-integrated graphics processor was disabled to reduce the processor heat generation. The Intel Speedstep functionality remained enabled for the duration of the testing to get realistic CPU idle performance conditions.
Board voltage settings were configured as follows:
- CPU Core Voltage – 1.25 + 0.005
- VCCIN Voltage – 1.90
- DRAM Voltage – 1.55
- CPU Ring Voltage – 1.125 + 0.005
- CPU SA Voltage Offset – +0.100
- CPU IO Analogue Voltage Offset – +0.100
- CPU IO Digital Voltage Offset – +0.100
- PCH 1.05 Voltage – 1.120
While not equaling the performance of the top coolers, the NH-D15 manages to remain within 3-4C of those water-based systems. Its performance with the LNA cables lags a bit more, but the biggest difference was seen with the CPU throttling. The the LNA cables attached to the fans, the CPU speed throttled between 4-8% during the test runs, while no CPU-based throttling was encountered with the fans running full speed. This points to the case that the system is at its stable limits using the NH-D15 cooler under the stress tests being run.
Sound Testing
Noctua certainly knows how to design top performing coolers the don't kill your eardrums in the process. The NH-D15 is by no means loud with the fans running at full speed, barely audible over the other system fans. With the LNA cables attached, the unit is whisper quiet.
Haswell results are
Haswell results are suprising; the D15 is (slightly) outperformed by the U14, which is basically half of D14. Maybe some kind of mounting issue?
Pricing is not really much of a weakness when it outperforms more expensive AIOs.
I would like to see how it performs with a higher power CPU like LGA2011 or AMD.
The following is probably
The following is probably splitting hairs, but for a cooler on the upper end of performance and price, every detail is worth consideration. For example, there is some evidence that shows heat pipes work more efficiently in vertical versus horizontal orientations. For this cooler, I like that (when used with an Intel CPU, not sure about AMD) the orientation of the heat pipes allow the length of the actual CPU core located beneath the IHS to sit perpendicular to the axis of the heat pipes that pass through the base plate while also directing air flow in the typical front to back pattern. The IHS (Integrated Heat Spreader), lid, cap, slug, or w/e you want to call it is pretty much square, but the actual Intel CPU package hiding underneath it is an elongated rectangle. This relative perpendicular arrangement allows the CPU core to conduct heat more directly and evenly to all 6 of those heat pipes instead of mainly just the middle 2.
The Hyper212 EVO is not in the same league, but is a solid performer because it has direct contact heat pipes which also span most of the width of it’s base. However, it unfortunately has the heat pipes aligned parallel to the actual CPU core when installed in the typical front to back air flow orientation. This is why I eventually rotated mine 90 degrees so now the CPU core spans under all 4 heat pipes. The tradeoff is that it moves air vertically like a chimney and exhausts out of the top of my tower case.
Of course relative performance all depends on the particular case, fans, installed cards, and their orientations. Anecdotally, I can say it performs maybe a degree better like this despite a hot GPU being uncomfortably close to the Hyper212’s intake. But hey, it is essentially a chance for free performance. I should also add that my case has bottom and front intake fans with top and rear exhaust fans so there is a fairly coherent vertical component to air flow in my case already.