Warm Up Your MacBook

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Warm Up Your MacBook
18 Nov 2019
You’ve been there - after putting your backpack in a frigid car, walking against the Wisconsin wind, or biking across the frozen lake, you arrive at work. You rest your palms on the keyboard to begin typing your password, and recoil in pain from the sudden cold of the metal sucking the heat from your skin.
How do you quickly warm up a laptop? Make it do a lot of work.
Here’s a one-line, built-in command that will peg your CPU to 100%:
yes > /dev/null

Run that from a Terminal, and don’t forget about it heh. What the command does is repeatedly send the word yes over and over to the null device, using 100% CPU.
If you want to stress your Mac more quickly and get your CPU hotter, try the stress utility:
brew install stress
stress -c 6 -m 2 -t 300

This will start 6 threads that each peg your CPU to 100% and 2 thread that do memory malloc/free. It has a 300-second timeout (5 mins) in case you walk away from your computer so it doesn’t overheat.
Bonus points, you can add an alias to your ~/.bash-profile to automate these options:
alias warm='stress -c 6 -m 2 -t 300'

fred: bash$ warm
stress: info: [65121] dispatching hogs: 6 cpu, 0 io, 2 vm, 0 hdd

Happy winter!

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The document provides methods for quickly warming up a MacBook, addressing the issue of the device feeling cold after exposure to cold environments. The primary strategy involves intentionally loading the central processing unit to generate heat. One immediate method is utilizing a built-in command accessible via the Terminal that forces the CPU to reach 100 percent utilization. This is achieved by executing the command yes > /dev/null, which repeatedly sends the word yes to the null device, thereby consuming 100 percent of the CPU resources.

For a more intensive method of thermal stress, the document recommends installing the stress utility using the homebrew package manager. This utility can be invoked to initiate a more complex load test. Specifically, the command stress -c 6 -m 2 -t 300 is suggested. This command is designed to stress the system by simultaneously running six threads at 100 percent CPU load and two threads dedicated to memory allocation and deallocation. The utility incorporates a timeout mechanism of three hundred seconds to prevent excessive overheating if the user abandons the process.

To streamline the process of warming up the machine, the text suggests automating these stress operations by creating an alias. This alias can be added to the user's bash profile file, such as ~/.bash-profile, with the command alias warm='stress -c 6 -m 2 -t 300'. This automates the initiation of the stress routine with a simple command, allowing the user to quickly engage the necessary system load. The text illustrates the outcome of running this command, showing the system dispatching the requested CPU hogs and memory operations.