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# How to Max out All CPUs on a Mac (from the Terminal)
- URL: https://birchtree.me/blog/max-cpu-mac-terminal/
- Published: 2015-10-29T09:00:00.000Z
- Updated: 2015-10-29T09:00:00.000Z
- Author: Matt Birchler
- Tags: mac, #Import 2023-06-01 22:41, #Import 2025-03-29 19:29

Have you ever needed to max out all your CPU cores? You landed on this page, so I suspect you have a good reason! Let’s just get right to it.

You want to open up the Terminal app (found in Applications>Utilities, or just use Spotlight) and paste this text into the console and hit return:

`yes > /dev/null &`

This will max out one of your CPU cores. Repeat the process again for each core you would like to max. My computer has 4 cores, so I ran it 4 times. If all has gone well, your Terminal should look something like this:

![](http://d.pr/i/1eggB+) 

You won’t see anything there, so in order to verify everything is working, open up Activity Monitor (also in the Utilities folder) and you should see a few processes called “yes” at the top inside the CPU tab.

![](http://d.pr/i/1l7TH+) 

These processes will run forever if you don’t do anything, which I’m guessing is not what you want. Simply run this command to stop each process immediately:

`killall yes`

That’s it, you’re Mac will be back to normal.