Because most fans used with videocards are fairly quiet we're omitting the fan noise recordings for this segment of heatsinks. Instead, FrostyTech will emphasize its reliance on cold hard facts when evaluating different thermal solutions by providing the following noise level measurements taken with a digital sound level meter in a noise-proof chamber.

FrostyTech.com VGA 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. Information on Frostytech's test methodology is available here.
manufacturer:	model no.:	*fan speed:	noise level (dba):
Zalman	VF700-AlCu	low	32.6 dB	Quiet
Zalman	VF700-AlCu LED	low	32.9 dB
Zalman	VF900-Cu	low	33.5 dB
Zalman	VF900-Cu	high	42.0 dB
Zalman	VF700-AlCu	high	43.1 dB
Zalman	VF700-AlCu LED	high	43.3 dB
Albatron	Stock FX5900 Heatsink		48.0 dB	Loud
			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.

With the Zalman VF900-Cu heatsink running at its stock 2400RPM speed, noise is just about negligible from outside the case - 42.0 dBA. Yet by using the Zalman Fan Mate 2 we can reduce the fan impeller speed to just 1350RPM, and decrease VF900-Cu's fan noise to barely over 33 dBA!

Surface Finish Comparator Notes: Flatness and Finish

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 Zalman VF900-Cu VGA heatsink has a surface roughness of approximately ~2 microinches, which is considered excellent. Next, let's see how this VGA heatsink handles the heat compared to a small selection of other videocard heatsinks!