Mac Performance Guide

Check GPU usage on a Mac

Short answer

In the app: open Activity Monitor and choose Window › GPU History. In the terminal, without sudo, read the GPU's own utilization statistic with ioreg. For GPU frequency and power, use sudo powermetrics.

From the terminal

Utilization, no sudo

ioreg -rc IOAccelerator | grep -o '"Device Utilization %"=[0-9]*'

"Device Utilization %"=18

It is an instantaneous value, so watch it for a while:

while true; do ioreg -rc IOAccelerator | grep -o '"Device Utilization %"=[0-9]*'; sleep 1; done

The full PerformanceStatistics dictionary (ioreg -rc IOAccelerator -d 1) also has Renderer Utilization %, Tiler Utilization % and GPU memory in use.

Which GPU you have

system_profiler SPDisplaysDataType | head -12

      Chipset Model: Apple M4 Max
      Type: GPU
      Total Number of Cores: 40

Frequency and power, needs sudo

sudo powermetrics --samplers gpu_power -n 1

powermetrics -h describes this sampler as "gpu power and frequency info". Add --show-process-gpu with the tasks sampler for per-process GPU time.

Reading the numbers

On Apple Silicon the GPU shares memory with the CPU, so "GPU memory" is part of your normal RAM. Short spikes are normal whenever windows animate; WindowServer itself uses the GPU to composite the screen. Sustained high utilization with nothing obvious open usually points to a browser tab, a game or a background render.

The easier way: GaugeMon

GaugeMon puts GPU usage in your menu bar without sudo. Its GPU page names the GPU and its core count and charts device, renderer and tiler utilization over the last 10 minutes, or on Apple Silicon the GPU's frequency, power in watts and temperature, with memory in use and allocated alongside.

GaugeMon's GPU page: device, renderer and tiler utilization charted, with frequency, power, memory and the GPU's name and core count

Download GaugeMon free trial Learn more