Raspbian Buster 64 bitJanuary 25, 2021 | Cluster
By default Raspbian currently only take advantage of 32 bit in the core and user land event thou it has an 64 bit CPU in the latest PPi 4. Depending of the purpose of your Raspberry Pi, you may want to take advantage of the 64 bit ARM architecture ( you may be developing some applications or maybe want to use it for container deployments), if you are not sure about if it is nessesary, don't do the following..
Run the following upgrade command:
Read and confirm.
Edit the boot configuration..
sudo nano /boot/config.txt
and add the following line:
(you can also boost the mhz from the default 700 to up about 1500 without CPU throtteling)
check the OS info:
uname -a sudo reboot
and check the the OS info again.