Install nvidia-smi on OSX I tried installing nvidia-smi with home-brew, but it is not working out, this is my output 

-bash: nvidia-smi: command not found


I have CUDA 7.5 installed and this is the output of my nvcc -V command 

Mine is a 15" Macbook Pro Retina, with Nvidia 750M GPU


  nvcc: NVIDIA (R) Cuda compiler driver
  Copyright (c) 2005-2015 NVIDIA Corporation
  Built on Thu_Sep_24_00:26:39_CDT_2015
  Cuda compilation tools, release 7.5, V7.5.19


Output of kextstat command

    kextstat | grep -i cuda
  140    0 0xffffff7f82675000 0x2000     0x2000     com.nvidia.CUDA (1.1.0) 5AFE550D-6361-3897-912D-897C13FF6983 &lt;4 1&gt;


OS version 10.11.4
In Macs there is no nvidia-smi command that comes with nvidia drivers. However, you could check this open-source alternative : https://github.com/phvu/cuda-smi

Edit in 2020 : 
As an alternative to nvidia-smi is Activity Monitor. Search on spotlight (cmd + space) and type Activity Monitor. When the program opens press cmd + 4. This will show you the active usage of GPU(s) on your system.
I think this feature comes with High Sierra 10.13 prior to that there is no option for gpu history.