Acoustic Samples: Listen to this Heatsink!

The Thermalright MST-9775 LE heatsink is equipped with a 92mm PWM fan that can vary in speed from 500-2500RPM. For this review, Frostytech tested the MST-9775 LE with a standard 3-pin fan power supply, so rotational speeds were kept at the default level only. Under these conditions, the Thermalright heatsink maintained a moderate noise level of about 46 dBA. To listen to this heatsink in operation, be sure to click on the little headphones icon below and play the sample MP3 file of the heatsink in operation.

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 an estimated 2500 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
Verax	Helado		36.3 dB	Intel/AMD
Intel	Stock Core 2 Duo		36.7 dB	Intel
Scythe	Mine Rev.B		36.8 dB	Intel/AMD
Scythe	Katana II		37.9 dB	Intel/AMD
Scythe	Kama Cross		40.0 dB	Intel/AMD
Noctua	NH-U12P	high	40.7 dB	Intel/AMD
Coolink	Silentator	high	41.2 dB	Intel/AMD
Glacialtech	Igloo 5710 Silent		43.4 dB	Intel/AMD
Coolermaster	Hyper48		43.6 dB	Intel/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
Glacialtech	Igloo 5062 Cu Light		45.2 dB	Intel
Noctua	NH-U12		45.4 dB	Intel/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
Thermalright	MST-9775 LE		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
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
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
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
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
Zalman	CNPS7500-Cu LED	high	50.9 dB	Intel/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
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	SLC-747	high	52.2 dB	Intel/AMD
Zalman	CNPS9700NT	high	52.2 dB	Intel/AMD
Cooljag	Falcon 92-Cu	high	52.8 dB	Intel/AMD
Zalman	CNPS9500 AT		53.3 dB	Intel
Glacialtech	Igloo 5057 E		53.4 dB	Intel
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
Xigmatek	AIO-S80DP	high	55.0 dB	Intel/AMD
Verax	Quattro 1	high	55.4 dB	Intel/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
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	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
Enzotech	Ultra-X	high	59.2 dB	Intel/AMD
Akasa	AK-920	high	59.2 dB	Intel/AMD
Coolermaster	Aquagate Mini R80	high	59.2 dB	Intel/AMD
Glacialtech	Igloo 5610 PWM	high	59.5 dB	Intel
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
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 92mm fan running at default RPM, the Thermalright MST-9775 LE heatsink produced 46.5 dBA noise. For the sake of comparison, the stock Intel Pentium D heatsink operates at around 47.5 dB.

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 base of the Thermalright MST-9775 LE heatsink has a machined base with a surface roughness of approximately 63 microinches, which is considered satisfactory. Next, let's see how this heatsink handles the heat compared to a selection of other Intel CPU coolers!