TweakTown uses a different method for testing CPU heatsinks which allows for an even playing field across all product tests. We feel that by using the same ambient temperature and strict lab-like testing procedures we are able to accurately compare one product to another. More information on our testing procedure can be found in the T.E.C.C. article here.
This was a first for me, and the results were tested multiple times with the results being the same each time. On our TECC test system the ZEROtherm cools the CPU better at full load than idle! The reason why will become apparent further down when we see what the fan is actually doing.
The idle temperatures are average for enthusiast coolers we've tested previously, but the load temps are top notch. This is actually the second lowest load temp we have seen so far; the only cooler that has produced a better load number is the Sunbeam Core-Contact Freezer.
The acoustic test shows us why the load and idle temperatures are so far from "normal". At 7 volts, a typical PWM voltage for the idle state, the fan produces only 41 dB, but when simulating a load environment with 12 volts the fan climes to 59 dB. At the high 50's, low 60's mark the cooler is still quiet, but not HTPC quiet. In a traditional enthusiast system or even one built for a semi-quiet, computer room environment, the ZEROtherm ZEN FZ 120 will not produce noticeable noise over other components or the background environment.