On Windows/Linux, there is a program called nvidia-smi for checking the memory and general statistics of GPUs.

There is no such thing on MacOS.

This program tries to bring that ability to MacOS. The main functionality is to display memory usage of each GPU.

Pre-built binary can be downloaded from here.

Run

./compile.sh

The output file is cuda-smi. Feel free to copy it to somewhere in your PATH directories.

When you run cuda-smi, it will give something like this:

$ cuda-smi
Device 0 [PCIe 0:1:0.0]: GeForce GT 750M (CC 3.0): 1584.6 of 2047.6 MB (i.e. 77.4%) Free

Your mileage may vary.

I based this on al42and's project.