The Mac Pro comes with the BIOS successor EFI 1.1 and handles booting differently from the conventional BIOS-based PC.[32]

Apple's Boot Camp provides BIOS backwards compatibility, allowing dual and triple boot configurations. These operating systems are installable on Intel x86 based Apple computers:[33]

  • Mac OS X 10.4.7 and later
  • Microsoft Windows XP, Vista, and Windows 7 32-bit & 64-bit (hardware drivers are included in Boot Camp)
  • Other 80x86 operating systems such as Linux x86, Solaris, DOS, BeOS, and BSD

This is made possible by the presence of an x86 Intel architecture as provided by the CPU and the BIOS emulation Apple has provided on top of EFI.[33] Installing any additional operating system other than Windows is not supported by Apple, because the Boot Camp drivers are Windows only.[33] It is often possible to achieve full or nearly full compatibility with another OS by using 3rd-party drivers.[33]

There are a number of challenges that one must face when trying to establish a multi-booting configuration on a single hard drive that uses the new GPT partitioning standard that Mac OS takes advantage of at the same time as the MBR, which is commonly used by Windows and Linux (though Linux can use GPT). One must synchronize their GPT and MBR partition tables multiple times during the setup of such configurations. The key challenge is that a maximum of 4 partitions can be made on any such hard drive (including the EFI partition).[34][35]This is because logical and extended MBR partitions are not possible which means that more than 4 partitions cannot be referenced for the MBR component of the configuration. Thus, having more partitions would force MBR and GPT to have differing partitioning schemes. The Disk Utility command-line application in Mac OS X (in addition to numerous 3rd-party graphical packages) can nondestructively resize a single partitioned HFS+ formatted volume to a scheme usable for dual/triple boot configurations with BIOS/MBR.