Last Updated on April 22, 2017 by Dave Farquhar
If you run the Raspberry Pi as a small server, you may want to throttle the CPU when it’s not under load to save energy. Throttling the Raspberry Pi is easy and only requires changing a few settings in /boot/config.txt.
Here’s what I did with mine.
The lines I added are in boldface.
#uncomment to overclock the arm. 700 MHz is the default.
arm_freq=700
arm_freq_min=100
#
# for more options see http://elinux.org/RPi_config.txt
core_freq=250
core_freq_min=75
sdram_freq=400
over_voltage=0
avoid_safe_mode=1
gpu_mem=192
overscan=1
If you run your Pi without a display, here’s a config that will save more power and memory by throttling the GPU and reducing its memory consumption:
#uncomment to overclock the arm. 700 MHz is the default.
arm_freq=700
arm_freq_min=100
#
# for more options see http://elinux.org/RPi_config.txt
core_freq=75
core_freq_min=75
sdram_freq=400
over_voltage=0
avoid_safe_mode=1
gpu_mem=16
overscan=1
I also found this very thorough guide to saving memory and CPU cycles on the Pi. By replacing common OS components with lighter-weight alternatives, it’s possible to save around 16 MB of RAM, and more importantly, save some CPU cycles. Emulation tasks tend to run the CPU to nearly 100%.
David Farquhar is a computer security professional, entrepreneur, and author. He started his career as a part-time computer technician in 1994, worked his way up to system administrator by 1997, and has specialized in vulnerability management since 2013. He invests in real estate on the side and his hobbies include O gauge trains, baseball cards, and retro computers and video games. A University of Missouri graduate, he holds CISSP and Security+ certifications. He lives in St. Louis with his family.