Testing and Results

Methodology

Testing CPU coolers is a fairly simple process. We boot the computer into the operating system and use SpeedFan to measure the processor’s temperature – at idle and load. The CPU cooler which gives the lowest temperature is obviously the better one in terms of cooling performance.

The ‘idle’ processor state is achieved by running the system in the OS for 30 minutes with no applications running – except Windows’ needed ones. Once those 30 minutes are over, we run SpeedFan (a CPU temperature monitor utility) and note the CPU’s temperature.

The ‘load’ state is achieved similarly to idle. However, instead of no applications running for 30 minutes, we run a utility called ‘CPU Burn-In’ on each core of the processor. This puts the CPU under the highest stress threshold and therefore outputs its highest possible temperatures. The temperature is recorded again, after 30 minutes and by using SpeedFan.

A low temperature is not only what makes a CPU cooler better than another. More importantly – especially in today’s world of HTPC’s – noise is an important issue to take into account. Unfortunately though, measuring the noise output from CPU coolers needs very expensive sound recording equipment. And because the coolers usually generate less than 30dBA, the price tag for one piece of equipment is one Tech-Reviews at the moment cannot possibly afford. Therefore, the only way for us to give you a verdict on a CPU cooler’s sound output is for us to use our God given human ears and compare the cooler in testing with other competitor models. This result is by no means scientific, but it’s certainly a good representation of how quiet a cooler is in relation to other competitor models.

Throughout the testing of this CPU cooler and the other ones mentioned in the results, the current testing variables were as follows:

• Ambient (testing environment) temperature: 20 Degrees Celsius.
• Thermal Paste: Tuniq TX-2
• Processor: AMD 7750+ Black Edition
• Stock Speed: 2.7ghz (200*13.5)
• Overclocked Speed: 3ghz (200*15)

Results

Temperatures

From the results with the processor at stock clock you can clearly see that the Zalman achieved the lowest idle result out of all the CPU coolers on test. The Scythe beat it at load with a three degree advantage – this could be an indication that the Zalman isn’t as good at higher temperatures. Clearly, the Zalman definitely beat the Freezer Xtreme by a long way.

At overclocked the Zalman’s results are a little less impressive with it drawing with the Mugen 2 at idle and being beaten by two degrees at load. This reinforces the point I made earlier with it struggling to deal with higher temperatures. Interestingly, the CNPS9900’s load temperature is less than the Freezer Xtreme’s idle temperature!

Noise

The Zalman CNPS9900 LED was the loudest of the three coolers. When listening hard, you can hear a ‘motor noise’ which suggests that the fan is not lubricated properly and rubbing. Although it was the loudest of the three, don’t get me wrong, the Zalman is still a very quiet cooler and one I’d recommend for quietness.

LED’s

When running, the Zalman CNPS9900 LED emits a soft blue glow. This surely would look appealing in any user’s computer case.