How do you install a 64-bit OS on a Raspberry Pi 4?

Question

ajcc · Accepted Answer

The 64-bit version of Raspberry Pi OS is currently in beta and the latest builds are linked from this forum post: https://www.raspberrypi.org/forums/viewtopic.php?p=1761738&sid=5bbfb3aaeff3e99239ed9229688a12f7#p1761738 , these images might require the Raspberry Pi Imager Tool to be written to an SD-card [https://www.raspberrypi.org/blog/raspberry-pi-imager-imaging-utility/ ].

The beta images seem a bit outdated and a user recommended doing a full upgrade: https://www.raspberrypi.org/forums/viewtopic.php?p=1797105#p1797105

misaz · Answer

I don't recommend. I am running aarch64 kernel on Raspberry Pi 4 now for about 4 months and there are no disadvantage but there are also no benefit. I do not remember how I did it exactly but I did not need any external tool. Please also note that this will enable you only 64bit kernel. All applications (chromium for example) are still 32bit because there are no (or at least I do not remember any update on it) userland libraries like libc which also must be recompiled to aarch64. So you will run 64bit kernel, but otherwise everything non-kernel related will still be only 32bit. Even if you want compile your own hello world using aarch64 compiler it still won't work until you will install aarch64 libc to your system. Running aarch64 and armv7 shared libraries in one system is very complicated. I think that there are no benefit of running 64bit software on Raspbian and this is probably reason why migration is so slow. If you need aarch64 for some reason you can use other distributions which natively compile in aarch64 everything for raspberry pi. I currently wait for Debian 11 release and then migrate from Raspbian to Debian. When debian become support Raspberry Pi, it will have more software and more frequently updated software than Raspbian. It will also natively run everything compiled for aarch64. If you think about performance, consider using ramdisk and upgrading sd card rather. CPU is fast enough even in armv7 mode.