:func:`shutil.copyfile`, :func:`shutil.copy`, :func:`shutil.copy2`,
:func:`shutil.copytree` and :func:`shutil.move` use platform-specific
fast-copy syscalls on Linux, Solaris and OSX in order to copy the file
more efficiently. All other platforms not using such technique will rely on a
faster :func:`shutil.copyfile` implementation using :func:`memoryview`,
:class:`bytearray` and
:meth:`BufferedIOBase.readinto() <io.BufferedIOBase.readinto>`.
Finally, :func:`shutil.copyfile` default buffer size on Windows was increased
from 16KB to 1MB. The speedup for copying a 512MB file is about +26% on Linux,
+50% on OSX and +38% on Windows. Also, much less CPU cycles are consumed
(Contributed by Giampaolo Rodola' in :issue:`25427`.)
