[withinboredom]

Wouldn’t that seriously hurt laptop battery life to use a discrete gpu to render the UI? Or is there someway to tell the OS that a non-discrete gpu is fine?

[capableweb]

No, GPUs are more power efficient than CPUs to render graphics, so it'll save battery.

[withinboredom]

So, my laptop is dumb for turning off the discrete GPU when I unplug it?

[Chai-T-Rex]

They didn't say discrete GPU, they said GPUs, which includes integrated GPUs.

[withinboredom]

A game engine will tell the OS to start up the discrete GPU if it is available. This is why I asked the original question. Is there some way to turn that off?

[OvermindDL1]

When initializing a GPU context you can specify whether you want the most efficient device, the fastest device, etc, for a GUI app then you would want to pick the most efficient, which is a single flag to pass in, or supply options and let the user pick which one they want.