Acoustic Samples: Listen to this Heatsink!

The Asus Silent Knight II heatsink is moderately audible at full speed (2300RPM), and somewhat quieter when the fan runs at a reduced speed on PWM compatible motherboards. For the purposes of these tests, the Zalman Fanmate 2 was used to decrease voltage to the 92mm PWM fan. To listen to this heatsink in operation, be sure to click on the little headphones icon below and play the sample MP3 files.

frostytech acoustic sampling chamber - full 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 2300 rpm.

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 est. 800 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
Arctic Cooling	Silencer 64 Ultra TC	low	27.6 dB	AMD
Scythe	Orochi SCORC-1000		27.8 dB	Intel/AMD
Scythe	Zipang		33.1 dB	Intel/AMD
Glacialtech	Igloo 5750 Silent		35.5 dB	Intel/AMD
Verax	Helado		36.3 dB	Intel/AMD
Glacialtech	Igloo 7311 Silent		36.5 dB	AMD
Intel	Stock Core 2 Duo		36.7 dB	Intel
Scythe	Mine Rev.B		36.8 dB	Intel/AMD
Glacialtech	Igloo 7222 Light		37.7 dB	AMD
Scythe	Infinity SCINF-1000		37.8 dB	Intel/AMD
Scythe	Katana II		37.9 dB	Intel/AMD
Scythe	Shuriken	high	38.2 dB	Intel/AMD
Scythe	Andy Samuri Master SCASM-1000		38.4 dB	Intel/AMD
Scythe	Kama Cross		40.0 dB	Intel/AMD
Noctua	NH-U12P	high	40.7 dB	Intel/AMD
Asus	Silent Knight 2	low	41.0 dB	Intel/AMD
Asus	Triton 77	high	41.2 dB	Intel/AMD
Coolink	Silentator	high	41.2 dB	Intel/AMD
Scythe	Ninja Mini		41.7 dB	Intel/AMD
Gigabyte	NeonCooler 8-BL		42.0 dB	AMD
Arctic Cooling	Freezer 64 LP		42.6 dB	AMD
Asus	Silent Square EVO	high	42.8 dB	Intel/AMD
Auras	SMF-660		43.4 dB	Intel
Glacialtech	Igloo 5710 Silent		43.4 dB	Intel/AMD
Coolermaster	Hyper48		43.6 dB	Intel/AMD
Auras	LPT-709		43.9 dB	Intel/AMD
Arctic Cooling	Alpine64		43.9 dB	AMD
Arctic Cooling	Alpine 7 Pro	high	44.1 dB	Intel
Thermalright	Ultra 120 Extreme		44.5 dB	Intel/AMD
Akasa	Revo (horizontal)	high	44.5 dB	Intel/AMD
Thermalright	SI-128SE		44.5 dB	Intel/AMD
Dynatron	A22		44.5 dB	AMD
Glacialtech	Igloo 5610 Silent		44.7 dB	Intel
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
Glacialtech	Igloo 5062 Cu Light		45.2 dB	Intel
Noctua	NH-U12		45.4 dB	Intel/AMD
Ajigo	MF043-044		45.4 dB	AMD
Spire	SP741B3		45.6 dB	AMD
Coolermaster	Hyper 212		45.9 dB	Intel/AMD
Scythe	Shogun	high	45.9 dB	Intel/AMD
Rosewill	RCX-Z2-EX	high	45.9 dB	Intel/AMD
Scythe	Mugen		46.0 dB	Intel/AMD
Asus	Silent Knight 2	high	46.2 dB	Intel/AMD
Thermalright	MST-977SLE		46.5 dB	Intel
Intel	Stock Pentium D	high	47.5 dB	Intel
Akasa	AK-975CU	high	47.7 dB	Intel
nPowertek	TTIC NPH-1000		47.5 dB	Intel/AMD
Scythe	Kama SCKK1000		47.5 dB	AMD
3Rsystem	Iceage 120	high	47.9 dB	Intel/AMD
Zalman	CNPS8700 LED	high	48.1 dB	Intel/AMD
Akasa	AK-965	high	48.1 dB	Intel
Akasa	AK-876	high	48.2 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
Coolage	Frozen Orb F0-Z924AL	high	48.9 dB	Intel
Spire	SP601B3		48.9 dB	Intel/AMD
Apack	Zerotherm Nirvana 120		49.2 dB	Intel/AMD
Asus	Triton 75		49.6 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
Xigmatek	HDT-S963	high	50.2 dB	Intel/AMD
Evercool	Buffalo HPEA-10025		50.2 dB	AMD
Zalman	CNPS9500 LED	high	50.3 dB	Intel/AMD
Xigmatek	HDT-S1283	high	50.7 dB	Intel/AMD
Gigabyte	3D-Rocket		50.7 dB	Intel/AMD
Zalman	CNPS7700-Cu	high	50.7 dB	Intel/AMD
Zalman	CNPS7500-Cu LED	high	50.9 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
Tuniq	Tower 120	high	51.6 dB	Intel/AMD
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
Auras	LPT-700		52.2 dB	Intel
Auras	SLC-747	high	52.2 dB	Intel/AMD
Zalman	CNPS9700NT	high	52.2 dB	Intel/AMD
nPowertek	NPH K8-1		52.2 dB	AMD
Glacialtech	Igloo 5750 PWM	high	52.3 dB	Intel/AMD
Xigmatek	HDT-S983	high	52.7 dB	Intel/AMD
OCZ	Vendetta	high	52.8 dB	Intel/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
Glacialtech	Igloo 5057 E		53.4 dB	Intel
Jetart	JAX801		53.5 dB	AMD
Apack	Zerotherm BTF92 OC Ed	high	53.6 dB	Intel/AMD
Coolermaster	Hyper TX2		53.7 dB	Intel/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
Gigabyte	Volar GH-PSV21-FB	high	56.1 dB	Intel/AMD
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	Waturbo		57.5 dB	Intel
Antazone	AS-C1000		57.6 dB	Intel/AMD
Noctua	NH-U9		58.4 dB	Intel/AMD
Rosewill	RCX-Z3	high	58.6 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 R80	high	59.2 dB	Intel/AMD
Glacialtech	Igloo 5610 PWM	high	59.5 dB	Intel
AVC	Z7U3301001	high	59.9 dB	AMD
Rosewill	RCX-Z2		59.9 dB	Intel
Spire	Fourier IV SP607B3-C		60.2 dB	Intel/AMD
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.

The Asus Silent Knight II heatsink's 92mm fan spins at 2300RPM by default, which generates about 46.2 dBA noise. Compatible PWM motherboards may automatically reduce that speed to about 800RPM if CPU load is light, decreasing noise to as little as 41.0dBA. Next up, thermal test results...