Turn off optimized notes for raspberry pie

Time:2019-12-8

1. Turn off HDMI output

/opt/vc/bin/tvservice -o

2. Close the module

vi /etc/modules

#snd-bcm2835

3. Turn off USB current limit

Because the current of the USB interface of raspberry pie is limited by the USB current protection chip, a larger current can be achieved by bypassing the USB current protection chip (i.e. not letting the current flow through the current protection chip).

For the specific configuration, you need to modify the file / boot / config.txt, and add three lines at the end.

max_usb_current=1
current_limit_override=0x5A000020
avoid_warnings=2

 

Due to the limitation of power supply chip, the maximum current is 1.2A. Restart raspberry pie to take effect

4. Over frequency, mandatory dominant frequency (according to official document: https://www.raspberrypi.org/documentation/configuration/config-txt/overclocking.md)

Modify / boot / config.txt

arm_freq=1400

        Frequency of the ARM CPU in MHz; default value is 1000 for the Pi Zero and Pi Zero W, 700 for Pi 1, 900 for Pi 2, 1200 for the Pi 3, 1400 for the Pi 3B+, 1500 for the Pi 4B

core_freq=500

        Frequency of the GPU processor core in MHz, influences CPU performance because it drives the L2 cache and memory bus; default value is 250 for the Pi 1/Pi 2, and 400 for the Pi 3/Pi Zero/Pi Zero W; the L2 cache benefits only the Pi Zero/Pi Zero W/ Pi 1, there is a small benefit for SDRAM on the Pi 2/Pi 3, and there is no effect on the SDRAM on the Pi 4B

5. Turn off swap when using dietpi version

Temporary situation: swapoff – A

To permanently shut down the swap, you need to modify the swap device in the / boot / dietpi.txt and / dietpi / dietpi.txt files, and then restart it