No, it doesn't really matter which port you use to connect the monitor—both the motherboard and GPU can work with it.
No, it doesn't really matter which port you use to connect the monitor—both the motherboard and GPU can work with it.
The GPU contribution will be minimal. The screen will be handled by the processor.
It's important to note this. Connect your monitor to the separate GPU to receive the display signal, and utilize the external GPU.
Usually, the built-in graphics are turned off after installing a video card, meaning you can't connect your monitor to the onboard GPU. Use an adapter instead.