Many Macs include multiple GPUs, pairing the integrated graphics  found on most Intel processors with more powerful dedicated graphics processors from NVIDIA or AMD.
Now, thanks to the inclusion of Thunderbolt 3 across Apple’s Mac lineup and support in the latest versions  of macOS, almost any new Mac owner can add a GPU  to their Mac via an external Thunderbolt enclosure .
Unlike CPU (Central Processing Unit), the GPU (Graphics Processing Unit) refers to the graphics card and processes of a computer’s internal system. Understand Apple’s Mac and Macbook GPUs can vary depending on the model.
When dealing with multiple GPUs, it’s often helpful to know which one is working at any given moment, and how much each one is being utilized. There are many third-party apps  and utilities that can provide this information, but if you just need basic data on GPU usage, Mac’s built-in Activity Monitor utility is here to help.
Viewing GPU Usage on a Mac
Viewing the GPU usage isn’t as easy as one might think. There’s a simple process to get to the Activity Monitor that shows you the analytics.
- Access the “Finder” located in the lower left-hand corner of your Dock (looks like a half blue, half white face)
- Once there a window will appear and you will see “Applications” on the left-hand side
- At the bottom of the Applications folder, click on Utilities (a blue folder)
- Click on “Activity Monitor”
Mac GPU Usage in Activity Monitor
- To view the GPU usage in macOS, first launch Activity Monitor. You can find it in its default location (Applications > Utilities) or by searching for it with Spotlight.
- With Activity Monitor open and selected as the active application, choose Window > GPU History from the menu bar at the top of the screen, or press the keyboard shortcut Command-4.
- This opens a new window called GPU History, which displays a utilization history for each GPU currently available to your Mac. You can click and drag on the small dot between each graph to change its size.
- The GPU usage window will remain always on top by default, but you can toggle that behavior by selecting Window > Keep CPU Windows on Top from the menu bar.
The GPU History window isn’t the only handy display available via Activity Monitor. Similar windows are available for showing both current CPU usage (Command-2) and CPU usage history (Command-3).
As with the GPU History window, you can toggle the “always on top” status of these windows via the Windows drop-down in the menu bar.
The ability to monitor GPU usage in macOS is not only handy for seeing how work is being divided between multiple GPUs, but it can also help troubleshoot issues. For example, it can show you when your GPU is being taxed when it shouldn’t be based on the applications currently running.
Third-party tools like iStat Menus  can show more information about your GPU’s status, such as graphics memory usage and temperature, but for simple monitoring, look no further than the Activity Monitor.
Checking GPU – Other Methods
Many users have reported that GPU History does not appear in the “Window” tab while looking at the Activity Monitor. Using the same methods as above to access the Activity Monitor; click on the “Energy” tab to access the GPU.
If you would like to check which graphics card you’re currently running is simple too:
- Click on the “Apple” symbol at the uppermost right-hand corner of your screen
- Select the first option that appears; “About Mac”
- You will see “Graphics” and next to this will be the current graphics card that is running
It’s important to mention that some Mac and Macbook models only have one graphics processor such as the lightweight Macbook Air.
The Activity Monitor and Mac Health
One way to narrow down issues you’re computer is having is by checking the Activity Monitor. Whether it’s the CPU or GPU, processes that are running in the background of your computer will show signs of malfunction within these tabs.
Symptoms such as overheating can be related to the GPU. Going to the Activity Monitor, you can see how the processes are impacting your Mac’s energy. Aside from the current energy impact and the average impact; users can see which applications are compatible with App Nap (uses very little energy when open) and also those that are preventing the device from going to sleep.
If you notice an application with excessive usage it may be having an issue. Whether it is considered Malware, or simply a glitch, checking your system’s GPU may point you to the problem.
An application that is using a higher GPU is going to reduce your Mac’s battery life. As such; the application may have an issue and need to be force closed and rebooted or uninstalled depending on what you’d like to use it for.