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
Arctic Cooling	Silencer 64 Ultra TC	low	27.6 dB	AMD
Verax	Helado		36.3 dB	Intel/AMD
Scythe	Mine Cooler		36.8 dB	Intel/AMD
Scythe	Katana II		37.9 dB	Intel/AMD
Asus	Arctic Square	low	38.3 dB	Intel/AMD
Scythe	Kama Cross		40.0 dB	Intel/AMD
Gigabyte	NeonCooler 8-BL		42.0 dB	AMD
Arctic Cooling	Freezer 64 LP		42.6 dB	AMD
Coolermaster	Hyper48		43.6 dB	Intel/AMD
Arctic Cooling	Alpine64		43.9 dB	AMD
Dynatron	A22		44.5 dB	AMD
Asus	Arctic Square	high	44.9 dB	Intel/AMD
Zalman	CNPS7000B-CU	high	44.9 dB	Intel/AMD
Zalman	CNPS7000A-Cu	high	45.2 dB	AMD
Zalman	CNPS7000-Cu	high	45.2 dB	AMD
Akasa	AK-860SF		45.2 dB	AMD
Noctua	NH-U12		45.4 dB	Intel/AMD
Ajigo	MF043-044		45.4 dB	AMD
Spire	SP741B3		45.6 dB	AMD
Scythe	Shogun	high	45.9 dB	Intel/AMD
Rosewill	RCX-Z2-EX	high	45.9 dB	Intel/AMD
Intel	Stock Pentium D	high	47.5 dB	Intel
Scythe	Kama SCKK1000		47.5 dB	AMD
Apack	CF900	high	48.3 dB	Intel
Apack	CF800	high	48.4 dB	Intel
LS Cable	SHS-T700		48.5 dB	Intel
Thermalfly	I75DUH		48.7 dB	Intel
Spire	SP601B3		48.9 dB	Intel/AMD
Thermaltake	Silentboost K8		49.7 dB	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
Arctic Cooling	Freezer 64 Pro		50.9 dB	AMD
Evercool	K802-715		51.5 dB	AMD
Alpha Novatech	PRE9060M92P	high	51.5 db	Intel
OCZ	Tempest		51.6 dB	Intel/AMD
Scythe	Samurai SCSM1000	high	51.6 dB	AMD
Apack	Zerotherm BTF80		51.9 dB	Intel/AMD
Apack	Zerotherm BTF90		52.1 dB	Intel/AMD
Cooljag	Falcon 92-AL	high	52.1 dB	Intel/AMD
nPowertek	NPH K8-1		52.2 dB	AMD
Cooljag	Falcon 92-Cu	high	52.8 dB	Intel/AMD
Zalman	CNPS9500 AM2	high	53.2 dB	AMD
Zalman	CNPS9500 AT		53.3 dB	Intel
Jetart	JAX801		53.5 dB	AMD
Thermalright	Ultra 120		53.7 dB	Intel/AMD
nPowerTek	NPH-Big K8		54.0 dB	AMD
Rosewill	RCX-Z1	high	54.1 dB	AMD
Coolermaster	Hyper6	high	54.7 dB	AMD
Xigmatek	AIO-S80DP	high	55.0 dB	Intel/AMD
Verax	Quattro 1	high	55.4 dB	Intel/AMD
Arctic Cooling	Silencer 64 Ultra TC	high	55.5 dB	AMD
Evercool	Magic Cooler		55.5 dB	AMD
Cooljag	OAK-H2	high	55.6 dB	Intel
Cooljag	OAK-H	high	55.7 dB	Intel
Thermalright	Ultra-90	high	56.2 dB	Intel/AMD
Akasa	AK-960E		56.3 dB	Intel
Dynatron	SK-V24		56.4 dB	AMD
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
Vantec	Mach1	high	56.9 dB	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
Thermalright	SLK-948U		58.8 dB	AMD
Alpha	PAL-8150		58.9 dB	AMD
Enzotech	Ultra-X	high	59.2 dB	Intel/AMD
Akasa	AK-920	high	59.2 dB	Intel/AMD
Akasa	AK-873	high	59.2 dB	AMD
Coolermaster	Aquagate Mini	high	59.2 dB	Intel/AMD
AVC	Z7U3301001	high	59.9 dB	AMD
Rosewill	RCX-Z2		59.9 dB	Intel
Akasa	AK-922 (EVObue)	high	60.3 dB	Intel/AMD
Ajigo	MF064-074	high	60.3 dB	AMD
Thermalfly	F1-IACSHA	high	60.4 dB	Intel/AMD
Cooljag	SFO-Q	high	60.6 dB	AMD
Cooljag	SFO-H	high	60.6 dB	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
AVC	Z7U7414001 (stock AM2)	high	63.0 dB	AMD
Titan	TTC-K8ATB/825/SC		63.1 dB	AMD
Evercool	PT02-9232CP		63.3 dB	Intel
CoolJag	SFO-D(18SC)		64.0 dB	AMD
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
Thermaltake	Polo 735	high	68.0 dB	AMD
Thermaltake	Venus 12	high	68.1 dB	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 92mm PWM fan spinning at 2300RPM the Asus Arctic Square heatsink generates 44.9 dBA noise according to FrostyTech's real-world measurements. By way of comparison, the stock Intel Pentium D heatsink produces about 47.5 dB at its fastest speed, the stock AM2 heatsink 63.0 dBA. When fan speed is reduced to 1200RPM, the Arctic Square pushes out little more than 38 dBA noise.

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.