Here’s another microtip for you. If you have a recent Mac that supports automatic GPU switching, you might have decided that macOS isn’t smart enough about when it decides to switch. Maybe you run 1Password or The Hit List and can’t fathom why they need the high-powered GPU. So, when you head out on the road, you use gfxCardStatus to “pin” the operating system on the low-powered Intel GPU and give your battery a break.

The problem comes when you go to project a presentation. Suddenly, reliable macOS won’t do it. Try as hard as you can, click Detect Displays as often as you like - no projection, no secondary display.

Why? Because macOS requires the high-powered GPU to connect a secondary display like a projector. But there’s no visible error messages or feedback. The connection simply won’t work. To solve the problem just switch gfxCardStatus back to automatic mode.