We take our noise measurements with the sound meter positioned 1 foot from the graphics card. I measured the noise floor to be 32 dBA, thus anything above this level can be attributed to the graphics cards. The power supply is passive for the entire power output range we tested all graphics cards in, while all CPU and system fans were disabled.
A reading under load comes from running the 3DMark Fire Strike Ultra stress test for 30 minutes. An idle reading comes after leaving the system on the Windows desktop for 30 minutes.
When looking at noise levels we can see part of the reason why Palit's card runs so cool, despite its small heatsink – the fans do have to spin a little faster than I'd like, producing just over 44dB of noise. This isn't really that loud, but it is audible and the Gigabyte 1660 SUPER is noticeably quieter.
For reference, the two fans ramped up to 57%, or 1980rpm, when under load. There's no idle fan-stop mode either, as the fans instead would keep spinning at or around 1000rpm regardless of the GPU load.