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Is there a specific download for 64 bit Raspbian? Since Raspberry Pi 3 is 64 bit, but there is only one download for Raspbian available, is there a 64 bit version? Or, am I just confused and they found a way to intelligently determine if the Pi is 32 bit or 64 bit to install Raspbian?

Human
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2 Answers2

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September 2020 Update

Beta versions are now available that install 64-bit versions of applications. Not all applications or libraries work.

Official forum post.

2020 Answer

No, there is not a "specific" download. All current versions of Raspbian include a 64-bit kernel (kernel8.img).

However, the Raspberry Pis do not, by default, use the 64-bit kernel.

The "official" way to have your Pi boot in 64-bit mode is to add a line arm_64bit=1 to /boot/config.txt. (Just make sure /boot/kernel8.img exists first).

There are a couple other "official" ways that are, imho, sub-par. For completeness:

  • Delete the 32-bit kernel images (in which case it will "fall back" to 64-bit)
  • Explicitly set kernel= to the 64-bit kernel

However, once running the kernel in 64-bit (confirmed with uname -m == 'aarch64'), you won't be able to really take advantages of the possible speed improvements (which, contrary to some popular belief, is real) unless you also install 64-bit binaries of the programs that you want to run.

For instance, to check if python is compiled to run on a 64-bit kernel or 32-bit:

python -c 'import struct;print(8*struct.calcsize("P"))'

I'm still looking for the official way to install 64-bit python (et. al) on 64-bit Raspbian.

Cameron Tacklind
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There is only a single download for Raspbian, but this includes ARM6 and ARM7 kernels.

If you look at the files installed in the boot sector there is support for all models, with different internal settings.

The Pi determines at boot time, the appropriate kernel and Device Tree settings for each model.

The Pi2 and Pi3 share a common kernel, and modules.

There is no specific 64 bit support. This has been discussed, but no convincing advantage for 64 bit support seems to exist. Indeed with 1GiB of memory, it is hard to see what advantage 64 bit would provide.

Milliways
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  • So I can use the same SD card for a 2 B and a 3 B? – Human Feb 10 '17 at 08:13
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    @Human I use the same image on most of my Pi. I customise config.txt using [pi2] and [pi3] to accommodate differences like enable_uart=1 – Milliways Feb 10 '17 at 08:35
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    I am curious if 64-bit support has changed now that we have the Raspberry Pi 4 with 4 GB RAM (and a forthcoming model with 8 GB RAM)? I do not see a clear answer anywhere in the official documentation. – Taylor D. Edmiston Aug 18 '19 at 23:25