Track GPU usage on a Mac with Apple Silicon

You’re running something GPU-heavy — Final Cut export, a Stable Diffusion model, a game — and you want to know whether the GPU is actually pegged or sitting half-idle waiting on something else. On Apple Silicon, GPU and CPU share memory and power budget, which makes “is the GPU the bottleneck” a real and useful question. macOS just refuses to give you a number anywhere convenient.

Here’s how to see it.

Two paths

The native way (powermetrics)

On Apple Silicon there’s no GPU tab in Activity Monitor. (There is one on Intel Macs with discrete graphics, which is misleading because most modern Macs are M-series now.) You can dig into the Window > GPU History floating panel on some macOS versions, but it’s coarse.

The accurate read comes from Terminal:

sudo powermetrics —samplers gpu_power -i 1000 -n 10

That dumps GPU active residency (the closest thing to ”% utilisation”), frequency, and power draw every second for ten samples. It’s the real data — Beacon reads the same source — but it needs sudo, the output is verbose, and you can’t leave it running ambient.

For VRAM-style questions, there isn’t really one — Apple Silicon’s unified memory means the GPU and CPU share the same pool, and you read that from regular memory tools.

The Beacon way

Beacon reads the GPU sampler and puts a live number in the menu bar.

1. Install Beacon on an Apple Silicon Mac (M1 or newer).
2. Open Settings > Menu Bar and enable GPU.
3. Choose what to show — percentage utilisation, a mini graph, or GPU frequency in MHz.
4. Click the GPU readout to see frequency, power draw in watts, and which processes are currently using the GPU.
5. Watch GPU and CPU side by side during heavy work — that's how you tell whether your bottleneck is graphics or compute.

A practical example: exporting a 4K timeline in Final Cut, you’d hope to see GPU around 90%+. If it’s sitting at 30% while CPU is also moderate, your bottleneck is probably disk reads or a CPU-bound effect, not raw GPU power. That diagnosis used to require a Terminal session; now it’s a glance up at the menu bar.

Worth flagging: on Intel Macs with discrete GPUs, Activity Monitor’s existing GPU tab is genuinely fine. Beacon’s GPU readout is most useful on M-series, which is where the native tooling is weakest.