Zalman CNPS9900 LED CPU Cooler

**Doctor Feelgood** · Posted: Mon, 05 Jan 2009 21:02:14 Post Subject: Zalman CNPS9900 LED CPU Cooler

The CNPS9900 LED features the familiar look of a Zalman product, with a variety of innovations and refinements that make it stand out over models from previous generations in the CNPS (Computer Noise Prevention System) product line. A 120mm fan is located in between two rings of thin copper fins that dissipate the processor's heat thanks to three heatpipe loops.

**Doctor Feelgood** · Posted: Sun, 01 Feb 2009 15:06:07 Post Subject:

I saw other tests of the Zalman CNPS9900 LED conducted minus the clear plastic shroud, so I decided to give it a shot. Image below show the cooler without it... Looks kind of awkward to me. No longer symmetrical, and the one ring is just off on its own off to that one side...

I retested on the same setup used in the review, and this time covered the following conditions (all with an ambient of 20 degrees C).

Â» 2000 RPM with the shroud
Â» 2000 RPM without the shroud
Â» 900 RPM with the shroud
Â» 900 RPM without the shroud

The chart below summarizes the results:

The cooler was noisy at 2000 RPM with the shroud, and got even louder without it! There was a terrible buzzing from the fins / fan vibrating. At 900 RPM the cooler was slightly quieter minus the shroud, but even with it installed it was very quiet. The temperatures at load minus the shroud dropped 2 degrees Celsius, so I would definitely recommend taking the shroud off if you planned to run at low speed.

This link is to a video of the fan running at 2000 RPM, then being switched to 900 RPM. The extra surge of noise during the transition is the video card, but that only lasts a second or two. You can hear that putting my hand on the cooler makes the vibration noise go away, which is exactly what the pressure from the shroud is doing (audio quality doesn't do this justice, but hopefully you get the idea)...

http://www.youtube.com/watch?v=M5B9NBdQJL0