I'm running into an issue which is seemingly because the viewport updates at unlimited FPS while moving mouse/camera, which is causing my GPU to be under heavy load, which is causing noise in my speakers. This may seem completely arbitrary to those that haven't seen this, but it's not limited to Houdini, and happens in other 3D applications that don't limit FPS in the viewport, e.g. Unity (in scenes that cause enough load).

Searching around the internet it seems to be a relatively common problem that can be resolved by running things with VSync on, but after looking through Houdini preferences I don't see any option to turn this on.

I should clarify, this only happens when moving the mouse, and it does not happen in frame-limited applications. I'm not sure if this is because the GPU draws a lot of power at peak load (RTX 4090), or if it's something else, but I'm able to reproduce this quite consistently, and even tried two external USB audio interfaces and it happens with both.

I wonder if there's any config for this?

You may be able to create a profile in Nvidia Control Panel that will apply when Houdini is active.