You can hear the fan at full load, especially on the M4 Pro. I really wish Apple went with a larger case and fan for that chip, which would allow quieter cooling.
That might be a recent phenomenon caused by the inevitable heat of the CPU getting closer and closer to its limit? Like explained in this video: https://youtu.be/AOlXmv9EiPo
My Mac Mini M2 never does any noise, even when I run FFMpeg the fans don’t spike. It just gets slightly warmer. Still, unless I’m doing these high CPU bound activities, every time I touch it it’s cold as if it was turned off, which is very different than my previous Intel one that was always either warm or super hot.
You can hear the fan at full load, especially on the M4 Pro. I really wish Apple went with a larger case and fan for that chip, which would allow quieter cooling.
Also, many units are affected by idle (power supply) buzzing: https://discussions.apple.com/thread/255853533?sortBy=rank
The Mac Mini is quieter than a typical PC, but it's not literally silent like, say, a smartphone.