Under Microsoft Windows, you can find this information by running the System Infor-
mation application (found in the Accessories > System Tools folder).
On the System
Summary screen, you can inspect the System Type field:
it will contain ”x64-based
PC” for a 64-bit CPU or
“x86-based PC” for a 32-bit CPU.
in Linux there is no standard application showing this information but
you can still infer it from the output of the uname -m command run on the terminal.
It will return x86_64 on a system with a 64-bit kernel (which can only run on a 64-bit
CPU), systems with a 32-bit kernel, it will return i386 or something similar (i486,
i586, or i686), and on systems with an arm64 kernel, it will return arm64. Any 32-
bit kernel can run on a 64-bit CPU, but since Apple controls the hardware and the
software, it is unlikely you will find this configuration.
Under Linux, you can inspect the flags field in the /proc/cpuinfo virtual file. If it
contains the lm attribute, then your CPU is a 64-bit; otherwise, it is a 32-bit. The
following command line will tell you what kind of CPU you have:
$ grep -qP ’^flags\s*:.*\blm\b’ /proc/cpuinfo && echo 64-bit
å || echo 32-bit
64-bit