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 has written professionally about computers since 1991, so he was writing about retro computers when they were still new. He has been working in IT professionally since 1994 and has specialized in vulnerability management since 2013. He holds Security+ and CISSP certifications. Today he blogs five times a week, mostly about retro computers and retro gaming covering the time period from 1975 to 2000.