Noctua NH-U12F: Quiet Air Cooling from Austria

CPU Cooling Test Configuration

The standard test bed for cooling tests uses an EVGA NVIDIA 680i SLI motherboard. This is primarily based on the consistent test results on this board and the excellent NVIDIA Monitor temperature measurement utility, which is part of the nTune program. The 680i chipset is also one of the better options for socket 775 CPU overclocking, and it provides great flexibility in our standard cooler tests which overclock to the failure limit with each cooler tested.


NVIDIA Monitor has a drop-down pane for temperature measurement which reports CPU, System, and GPU results. Reviews at this point will concentrate primarily on CPU temperature. In addition to the real-time temperature measurement, NVIDIA Monitor also has a logging feature which can record temperature to a file in standard increments (we selected every 4 seconds). This allows recording of temperatures during testing and play back, for example, of stress test results that can then be examined when the stress tests are completed. There is also the handy reference of speeds and voltages in the top pane to confirm the test setup.

NVIDIA Monitor was compared to test results from the Intel TAT (Thermal Analysis Tool). Intel TAT CPU portions do function properly on the EVGA 680i motherboard, but the chipset-specific features do not operate as they should. Idle temperatures in TAT were in line with measured idle temps with NVIDIA Monitor. The CPU stress testing with TAT pushing both cores showed TAT stress temps at 80% CPU usage roughly corresponded to temps reported in our real-world gaming benchmark.

Other components in the cooling test bed are generally the same as those used in our motherboard and memory test bed:

Cooling Performance Test Configuration
Processor	Intel Core 2 Duo X6800 (x2, 2.93GHz, 4MB Unified Cache)
RAM	2x1GB Corsair Dominator PC2-8888 (DDR2-1111)
Hard Drive(s)	Hitachi 250GB SATA2 enabled (16MB Buffer)
Video Card:	1 x EVGA 7900GTX - All Standard Tests
Platform Drivers:	NVIDIA 9.53
NVIDIA nTune:	5.05.22.00 (1/16/2007)
Video Drivers:	NVIDIA 93.71
CPU Cooling:	Noctua NF-U12F ASUS Silent Square Pro Scythe Ninja Plus Rev. B OCZ Vindicator Thermalright Ultra 120 Extreme Thermalright Ultra 120 Scythe Infinity Zalman CNS9700 Zalman CNS9500 Cooler Master Hyper 6+ Vigor Monsoon II Lite Thermalright MST-9775 Scythe Katana Tuniq Tower 120 Intel Stock HSF for X6800
Power Supply:	OCZ PowerStream 520W
Motherboards:	EVGA nForce 680i SLI (NVIDIA 680i)
Operating System(s):	Windows XP Professional SP2
BIOS	Award P24 (1/12/2007)

All cooling tests are run with the components mounted in a standard mid-tower case. The idle and stress temperature tests are run with the case closed and standing as it would in most home setups. We do not use auxiliary fans in the test cooling case, except for the Northbridge fan attached to the 680i for overclocking.

Noctua provided a small syringe of a generic-looking white thermal compound, so we tested the Noctua with our standard premium silver-colored thermal compound. In our experience the thermal compound used makes little to no difference in cooling test results. This is particularly true now that processors ship with a large manufacturer-installed heatspreader. Our only control on thermal compound is that we use the manufacturer-supplied product if they supply a premium product, or a standard high-quality thermal paste if a premium brand is not supplied.

We first tested the stock Intel cooler at standard X6800 speed, measuring the CPU temperature at idle and while the CPU was being stressed. We stressed the CPU by running continuous loops of the Far Cry River demo. The same tests were repeated at the highest stable overclock we could achieve with the stock cooler. Stable in this case meant the ability to handle our Far Cry looping for at least 30 minutes.

The same benchmarks were then run on the cooler under test at stock, highest stock cooler OC speed (3.73GHz), and the highest OC that could be achieved in the same setup with the cooler being tested. This allows measurement of the cooling efficiency of the test unit compared to stock and the improvement in overclocking capabilities, if any, from using the test cooler.

Push-Pull and High-Output Fan Tests

The Noctua NH-U12F is clearly designed with low noise as a primary design concern. The heatsink also makes it very easy to install two fans in a push-pull fan configuration, with the installation kit even including the extra pair of fan-mounting wires. To better understand the cooling capabilities of the Noctua, the heatpipe tower was therefore tested in three configurations:

1. Standard single fan configuration with the included NF-S12 fan
   
2. Two NF-S12 fans in a push-pull configuration
   
3. A single high-output/low-noise SilenX IXTREMA 72cfm/14 dB-A fan

Graphs and charts in this review will report three benchmark results with the Noctua cooler. This will allow an easy comparison of the effectiveness of different fan configurations on this cooler's performance. Since the new item for noise measurement in these tests is the Noctua NF-S12 fan, the only reported noise results are measurements of the heatsink using that fan. The push-pull dual Noctua-fan and SilenX fan results were also all below our system noise floor, but are not reported in charts. We are updating our test bed in the near future to allow a wider range of useful noise measurements for these cooler tests.

We also ran brief test results comparing the cooling efficiency and noise of the Scythe SFLEX SFF21F 64cfm/28 dB-A fan that was used in Thermalright reviews and the SilenX fan used in several of the most recent reviews. Cooling results were similar with either fan on the Noctua heatsink, with the SilenX providing better cooling on some overclocks. Both fans were quiet and came in below the noise floor of our test system, but the SilenX was subjectively quieter than the SFLEX. For these reasons the SilenX was chosen for the third series of tests. Those who prefer the SFLEX fans will find similar results to those reported in this review.

Noise Levels

In addition to cooling efficiency and overclocking abilities, users shopping for CPU cooling solutions may also be interested in the noise levels of the cooling devices they are considering. Noise levels are measured with the case open on its side and are measured using a C.E.M. DT-8850 Sound Level meter. This meter allows accurate sound level measurements from 35b dB to 130 dB with a resolution of 0.1 dB and an accuracy of 1.5 dB. This is sufficient for our needs in these tests, as measurement starts at the level of a relatively quiet room. Our own test room, with all computers and fans turned off, has a noise level of 36.4 dB.

Our procedures for measuring cooling system noise are described on the page reporting measured noise results comparing the stock Intel cooler and recently tested CPU coolers to the Noctua NH-U12F cooler.