Basically, you can expect the notebook to be rather noisy, both in normal and performance mode (45-55 dB and performance averages 65 dB), and it is recommended to use an external cooling system that blows air from below onto the unit.
However, it is possible to do this without.
The whole notebook is made up of many performance components that generate a lot of heat.
In normal operation, the temperature can rise to 93 degrees when several demanding services are open.

I have the notebook connected to power and a dock most of the time and run it in GPU Ultimate mode. For me, the "Quiet" mode is usually good enough for normal work and not very graphics intensive games. The laptop is to my left and about 40cm away. You can hardly hear the fans and they are around 33 decibels (in quiet mode). However, as soon as you go into "performance" or "turbo" mode, it becomes a bit of a jet and easily reaches the 55 dB mentioned above...but I rarely use this mode when I'm encoding a video.