Acoustic Samples: Listen to this Heatsink!

The Cooljag OAK-H2 heatsink is nearly inaudible when it's fan runs at the ultra low speed of something along the lines of 600-1800RPM, and the down side to this is that level of airflow is completely impractical for this heatsink geometry. The PWM fan is controlled by the BIOS so it is very quiet at its lowest RPM, and moderately loud at full speed (1800-3500RPM). To listen to this heatsink in operation at its lowest fan speed, click on the little headphones icon below and play the sample MP3 files.

frostytech acoustic sampling chamber - low speed
	standard waveform view of a 10 second recording. click on the headphones icon to listen to an mp3 recording of this heatsink in operation. the fan is rotating at an estimated 600 rpm

Sound Level Measurements: Which Heatsink is Quietest?

Listening to the actual noise a heatsink makes allows you to hear what pure numbers alone cannot get across. To further emphasize FrostyTech's reliance on cold hard facts when evaluating a heatsink, we also take noise level measurements with a sound level meter.

FrostyTech Heatsink Noise Level Measurements Noise level Decibel measurements of each heatsinks' fan in operation are taken with the aid of a sound level meter and sound isolating enclosure. The values may be higher than the mfgr's listed specs, but are directly comparable to one another. Measurements are made on the dB (A) scale, lower values are best. Information on Frostytech's test methodology is available here.
manufacturer:	model no.:	fan* speed:	noise level (dba):	cpu** platform
Cooljag	OAK-H2	low	29.2 dB	Intel
Verax	Quattro 1	low	30.9 dB	Intel/AMD
Verax	Helado		36.3 dB	Intel/AMD
Thermalfly	I75DUB		38.7 dB	Intel
Intel	Stock Pentium D	low	40.5 dB	Intel
Coolermaster	Hyper48		43.6 dB	Intel/AMD
Zalman	CNPS7000B-CU	high	44.9 dB	Intel/AMD
Noctua	NH-U12		45.4 dB	Intel/AMD
Scythe	Shogun	high	45.9 dB	Intel/AMD
Intel	Stock Pentium D	high	47.5 dB	Intel
Apack	CF900	high	48.3 dB	Intel
Apack	CF800	high	48.4 dB	Intel
Thermalfly	I75DUH		48.7 dB	Intel
Spire	SP601B3		48.9 dB	Intel/AMD
Zalman	CNPS7700-Cu LED	high	49.8 dB	Intel/AMD
nPowertek	NPH-775-1		50.1 dB	Intel
Zalman	CNPS9500 LED	high	50.3 dB	Intel/AMD
Gigabyte	3D-Rocket		50.7 dB	Intel/AMD
Zalman	CNPS7700-Cu	high	50.7 dB	Intel/AMD
Alpha Novatech	PRE9060M92P	high	51.5 db	Intel
OCZ	Tempest		51.6 dB	Intel/AMD
Apack	Zerotherm BTF80		51.9 dB	Intel/AMD
Apack	Zerotherm BTF90		52.1 dB	Intel/AMD
Zalman	CNPS9500 AT		53.3 dB	Intel
Thermalright	Ultra 120		53.7 dB	Intel/AMD
Verax	Quattro 1	high	55.4 dB	Intel/AMD
Cooljag	OAK-H2	high	55.6 dB	Intel
Akasa	AK-960E		56.3 dB	Intel
Zalman	CNPS9700 LED	high	56.5 dB	Intel/AMD
Zalman	FS-C77		56.5 dB	Intel/AMD
Gigabyte	3D Rocket-Pro	high	56.7 dB	Intel/AMD
Zalman	CNPS8000	high	57.4 dB	Intel/AMD
EKL	V8	high	57.5 dB	Intel/AMD
Sunon	Watrubo		57.5 dB	Intel
Antazone	AS-C1000		57.6 dB	Intel/AMD
Noctua	NH-U9		58.4 dB	Intel/AMD
Coolermaster	Aquagate Mini	high	59.2 dB	Intel/AMD
Thermalfly	F1-IACSHA	high	60.4 dB	Intel/AMD
Akasa	AK-961		60.7 dB	Intel
Thermaltake	Jungle512	high	60.8 dB	Intel
Gigabyte	3D Cooler-Pro	high	62.5 dB	Intel/AMD
Gigabyte	3D Cooler-Ultra	high	63.0 dB	Intel/AMD
Evercool	PT02-9232CP		63.3 dB	Intel
nPowertek	SF 775-2	high	64.6 dB	Intel
Gigabyte	GH-PCU23-VE	high	65.6 dB	Intel/AMD
ASUS	Starice	high	67.4 dB	Intel/AMD
Thermalfly	I75DUB	high	68.5 db	Intel
Gigabyte	G-Power Pro	high	71.9 dB	Intel/AMD
			noise level (dba)
*unless noted, for reference heatsinks with variable-speed fans only the 'high speed' (12V) fan noise measurement is included in the comparison sheet; more detailed results for the low fan speed (~5V) tests reside in each specific heatsink review. ** 'AMD' denotes compatibility with socket 754/939/940 & AM2 processors where applicable. 'Intel' denotes compatibility with socket 775 platform.

With its 93mm fan spinning at a very conservative 600-1800RPM, the Cooljag OAK-H2 heatsink generates 29.2 dBA. By way of comparison, the stock Intel thermal solution produces about 40.5 dB at its quietest speed. The Cooljag OAK-H2 may be quiet when its fan is barely turning, but we do not recommend you run it under these conditions - if you have a 3-pin fan header, find short length of wire to short the blue and yellow wires of the fan's power cord so it rotates at full speed. If you don't, your CPU may likely overheat.

Surface Finish and Flatness

Surface finish is an important factor that we all look for when holding a new heatsink. Flipping a cooler over to see how well the base has been machined is a quick way to judge the attention to detail that was put into making it. The following test involves the use of a Surface Roughness Comparator, which offers a concise cross section common machine surface finishes.

The Cooljag OAK-H2 heatsink has a surface roughness of approximately 16 microinches, which is considered very good. Next, let's see how this heatsink handles the heat compared to a selection of other heatsinks!