Fan-off for longer, near-silent when it spins: The Thermal Grizzly WireView Pro II Noctua Edition

First of all, the thermal mass and passive heat dissipation of the integrated heatsink enable the Noctua Edition to keep its fan completely off most of the time. While even the Noctua Edition eventually has to start up its fan at elevated heat loads or ambient temperatures, this takes much longer compared to the regular version.

To simulate a worst-case scenario, we disabled all the case fans in our system, which resulted in in-case temperatures of more than 40°C. In this extreme scenario, the Noctua Edition did not start up its fan at all at 200, 250 and 300W GPU load whereas the regular version had to start up its fan at 200W after 5 minutes and 40 seconds. At 300W, it only took 2 minutes and 15 seconds for the fan to start up. At 400 and 480W the temperature inside the case rose to 50 and 52°C respectively, and even the Noctua Edition had to start up its fan. However, it took 4 minutes and 25 seconds at 400W and 2 minutes and 50 seconds at 480W whereas the standard version had its fan running after 1 minute 40 seconds and 1 minute 25 seconds at these settings, so the cooling improvements of the Noctua Edition more than doubled the time until the device actually produced any noise at all at 400W and doubled it at 480W.

This advantage in thermal efficiency was also reflected in the recorded GPU connector temperature, which serves as the key input for the WireView’s fan control. As the chart below shows, the Noctua Edition ran cooler at all power levels, around 3°C on average.

But what about the noise levels when the fan actually ran? How much quieter is the Noctua Edition? Despite the extremely high temperatures inside the case, the Noctua Edition only had to run its NF-A4x10n fan at slightly below 2000rpm to keep the temperature of the connector in check. Since the noise emission of the fan is extremely low in this RPM range, we placed the microphone at a distance of only 10cm and measured ~21.5dB(A). Converted to a standard distance of 1m, this is just 1.5dB(A), which means that the fan would be completely inaudible over other fans in the system. The regular version ran its fan at around 5000rpm, which resulted in 39.4dB(A) measured from 10cm. Corresponding to a noise level of 19.4dB(A) at a distance of 1m, this is still very quiet, but might be slightly audible in extremely quiet systems.