MacMini Intel: All libraries and executables are universal?

在公司的 MacMini Intel 上发现几乎所有的库 (static/dynamic) 和可执行文件都是 Universal 格式的:

$ file /bin/bash
/bin/bash: Mach-O universal binary with 2 architectures
/bin/bash (for architecture i386): Mach-O executable i386
/bin/bash (for architecture ppc): Mach-O executable ppc
$ file /Applications/DVD\ Player.app/Contents/MacOS/DVD\ Player
/Applications/DVD Player.app/Contents/MacOS/DVD Player: Mach-O universal binary with 2 architectures
/Applications/DVD Player.app/Contents/MacOS/DVD Player (for architecture i386): Mach-O executable i386
/Applications/DVD Player.app/Contents/MacOS/DVD Player (for architecture ppc): Mach-O executable ppc
$ file /usr/lib/libz.1.2.3.dylib
/usr/lib/libz.1.2.3.dylib: Mach-O universal binary with 4 architectures
/usr/lib/libz.1.2.3.dylib (for architecture ppc): Mach-O dynamically linked shared library ppc
/usr/lib/libz.1.2.3.dylib (for architecture ppc64): Mach-O 64-bit dynamically linked shared library ppc64
/usr/lib/libz.1.2.3.dylib (for architecture i386): Mach-O dynamically linked shared library i386
/usr/lib/libz.1.2.3.dylib (for architecture x86_64): Mach-O 64-bit dynamically linked shared library x86_64
$ file /usr/lib/liby.a
/usr/lib/liby.a: Mach-O universal binary with 2 architectures
/usr/lib/liby.a (for architecture i386): current ar archive
/usr/lib/liby.a (for architecture ppc): current ar archive
$

不晓得这种 Universal 的格式的文件是否会比普通的格式大很多?