With the fan mounted flatly against the side of the heatsink there is cause for some turbulence right from the start - and hence noise is somewhat more noticeable than not. A plenum could help to alleviate this issue, but for the moment we'll have to make due. To listen to this heatsink for yourself, be sure to click on the little headphones icon below and download the MP3 file.

FrostyTech Acoustic Sampling Chamber
Standard Waveform view of a 10 second recording. Click on the headphones to listen to an MP3 recording of this heatsink in operation.

Sound Level Measurements:

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 Decibel readings with a sound level meter. These results may be higher than the manufacturer's listed specs, but then again these are real world measurements. Measurements are made on the dB (A) scale.

FrostyTech Sound Level Results
-	Manufacturer	Model	Noise Level	Scale
	Zalman	CNPS6500-AlCu	47.4/28.9 dB	quiet
	Intel	Socket 478	42.5 dB
	Arkua	848X-6B	49.3 dB
	Cho-Liang	CL-CB0094-1A	49.8 dB
	Cho-Liang	CL-CB00881	50.2 dB
	Taisol	CEP426151A	50.7 dB
	JMC	400094	50.8 dB
	Vantec	CCK-7025	51.4 dB
	Arkua	838T-7G	51.7 dB
	ChoLiang	CB0307Z17	52.9 dB
	Dynatron	DC1207BMW	53.0 dB
	Zalman	CNPS5700D-Cu	53.8 dB
	Globalwin	VA476	54.2 dB
	Dynatron	DC1206BMV	55.1 dB
	Glacialtech	Igloo 3300	55.4 dB
	ChoLiang	CB0309Z17	55.7 dB
	AVC	117140	56.1 dB
	CPUMate	DIA10500	57.5 dB
	NengTyi	NW6700	58.0 dB
	Coolermaster	IHC-H71	64.4 dB	louder

With our Omega sound meter in hand we measured the noise level of this heatsink at 57.5dB - not too bad for a Pentium 4 heatsink, but definitely on the louder side of the scale. Up next, the thermal results are in.