Unable to set your monitor as the primary display in Linux? Here's how to fix that

Maybe you are using a laptop that is connected to an external monitor. You want to use the monitor as your primary display on Linux, but it just won't let you. Let's fix that.

This solution will apply to devices with an NVIDIA graphics card.

1. Open NVIDIA X Server Settings.

2. Click on PRIME Profiles

3. Set NVIDIA (Performance Mode).

Restart your computer to apply the changes. I don't know why this needs a system restart, but it does.

When I installed Linux Mint, both displays worked perfectly out of the box, and I was able to use the Display Settings to set my monitor as the primary display, and turn the laptop's screen off (because its broken). Then I installed NVIDIA's drivers using Mint's built-in Driver Manager. However, when I restarted the laptop, it would not remember my display settings. It also wouldn't let the monitor work as the primary display, when I tried to, the internal display turned black, and the monitor's display sort of froze. No errors, nothing. I just had a black screen with a cursor. I tried messing with the settings, and ARandR, it didn't help. It was then I realized that NVIDIA's configuration was being silly.

NVIDIA X Server Settings, which is the name of the app you use to manage the GPU's options, is configured to operate with "NVIDIA - On Demand" by default. From its name, you would assume that the NVIDIA GPU is used when required, right? Yes, that's how it works. When you play games or do something that requires the GPU, it is activated. But, when you have a monitor connected via HDMI, literally to the GPU's port, you would expect it to recognize that and work. Instead, it still behaves as if On Demand mode is active, so the internal GPU, in this case, an Intel, is awake and handles the load. NVIDIA is idle. When the monitor is set to primary, the iGPU falls asleep, but NVIDIA doesn't awake. Snoozing on the job! A similar issue is described here.

I faced a few hurdles while installing Linux Mint. First the flashing issue which was caused by Secure Boot, then the requirement to disable RST, then the monitor issue. A little patience can do wonders, and I learned a few things.

Perhaps there are other solutions to this monitor issue out there.