The AMI BIOS on this motherboard allows for Smart Fan calibration, which tests the attached fan, determines its capabilities and makes a recommendation for power settings. The 1562/2368 detected min/max fan speed is within Zalman's claimed spec, and the suggested PWM values match those of the "Quiet" mode setting. The BIOS also has a "Performance" fan mode setting, which I will use for comparison. The processor will be tested in two different configurations, one completely stock (2.5Ghz @ 1.3v) and one overclocked (3.0Ghz @ 1.375v) state.
At stock processor speed and voltage the Quiet and Performance PWM modes only differ by 1° both at idle and under load. The CNPS9300 does a good job of keeping things under control, with idle temps below 30° C and load temperatures peaking only slightly above 40° C. When extra speed and voltage is applied, the 9300 scales well, giving up very little idle temperature performance, and topping out around 50° C at maximum utilization.
I was impressed with the performance of the Zalman CNPS9300 AT. For a cooler that is designed primarily with noise prevention in mind, CPU temperatures remained well under control even when overclocked pretty much at the maximum stable ceiling of this chip. Granted 1.375v is not a lot of voltage but this is a quad core 65nm processor we're talking about; heat can definitely be a factor. Fortunately the 9300 is well up to the task.
Unfortunately I would not consider the CNPS9300 a "noiseless" cooler, whether used in performance or quiet PWM modes. As can be seen from the testing results, there is very little difference between the two modes, and in fact the performance setting actually turned out to be the least annoying of the two. While idle conditions in either mode left the 9300 running down at the silent end of the spectrum, loading the CPU up to 100% caused the quiet mode to constantly fluctuate its power pulses. Like driving an automatic vehicle up a steep incline, the 9300 PWM always seemed to be hunting for the right rpm to use. Performance mode seemed to smooth things out more; at least the fan noise wasn't constantly changing in pitch. If you're looking for a quiet cooler for a computer that doesn't see a lot of processor utilization, the CNPS9300 AT works beautifully.
The quality and ease of installation of the CNPS9300 are trademarks we have come to expect from Zalman. The finish on the base is outstanding and the radial fins seem very sturdy, not prone to bending or breaking loose of their solder like some other brand coolers recently tested. The mounting clip provides plenty of tension and the centering post keeps the cooler perfectly oriented on the CPU IHS, while still allowing some amount of rotation for proper alignment. Incorporating a PWM smart fan is a welcome improvement over previous model's manual fan controllers.
I found the CNPS9300 online for $49.99 making it slightly less expensive than its popular 9500 and 9700 siblings. With its smaller size, less mass and lower price, the CNPS9300 is sure to be a big hit.
OCIA.net has awarded the Zalman CNPS9300 AT its Seal of Approval.