The GPU Juggle
Many high-end 15-inch and 16-inch MacBook Pro models are equipped with two graphics processors: an integrated, low-power GPU built into the CPU (usually Intel or Apple Silicon), and a high-performance, discrete GPU (like an AMD Radeon). By default, macOS employs a feature called “Automatic graphics switching.” To save battery life, the system constantly monitors your activity. If you are just typing a document, it uses the low-power GPU. The moment you open a video editor or plug in an external monitor, it automatically switches to the power-hungry discrete GPU. While this usually works well, it can sometimes cause slight stuttering during the switch, or drain your battery unnecessarily if a poorly optimized background app forces the discrete GPU to stay active.
Forcing the Discrete GPU
To ensure maximum, consistent performance (especially when plugged into the wall) and stop macOS from automatically switching between graphics cards to save power, you can force the system to always use the high-performance GPU.
Open System Preferences (or System Settings). If you are on an older version of macOS (like Monterey or earlier), click on Battery. On newer versions (like Ventura or Sonoma), look for the Battery or Displays section depending on your specific hardware. Look for a checkbox labeled Automatic graphics switching. (Note: This option will ONLY appear if your Mac actually has two distinct GPUs; if you have an M1/M2 Air, this does not apply). Click the checkbox to uncheck it. By disabling this feature, your Mac will permanently engage the high-performance discrete graphics card. This guarantees maximum graphical power at all times, though it will significantly reduce your battery life if you unplug the machine.