Intel-based Mac computers use very similar hardware to PCs from other manufacturers that ship with
Microsoft Windows or
Linux operating systems. In particular,
CPUs,
chipsets, and
GPUs are entirely compatible. However, Apple computers also include some custom hardware and design choices not found in competing systems: •
System Management Controller is a custom Apple chip that controls various functions of the computer related to
power management, including handling the power button, management of battery and thermal sensors, among others. It also plays a part in the protection scheme deployed to restrict booting macOS to Apple hardware (see
Digital Rights Management below). Intel-based Mac doesn't implement
TPM. • Laptop input devices. Early
MacBook and
MacBook Pro computers used an internal variant of
USB as a
keyboard and
trackpad interconnect. Since the 2013 revision of
MacBook Air, Apple started to use a custom
Serial Peripheral Interface controller instead. The
2016 MacBook Pro additionally uses a custom internal USB device dubbed "iBridge" as an interface to the Touch Bar and
Touch ID components, as well as the
FaceTime Camera. PC laptops generally use internal variant of the legacy
PS/2 keyboard interconnect. PS/2 also used to be the standard for PC laptop pointing devices, although a variety of other interfaces, including USB,
SMBus, and
I2C, may also be used. • May include Apple-exclusive Intel processors, and they may support
Intel Iris IGPU as well as
M-PCIe. • Additional custom hardware may include a GMUX chip that controls
GPU switching, non-compliant implementations of
solid-state storage and non-standard configurations of
HD Audio subsystem. • The
keyboard layout has significant differences between
Apple and
IBM PC keyboards. While PC keyboards can be used in
macOS, as well as Mac keyboards in
Microsoft Windows, some functional differences occur. For example, the (PC) and (Mac) keys function equivalently; the same is true for (PC) and (Mac) – however, the physical location of those keys is reversed. There are also keys exclusive for each platform (e.g. ), some of which may require software remapping to achieve the desired function. Compact and laptop keyboards from Apple also lack some keys considered essential on PCs, such as the
forward key, although some of them are accessible through the key. • Boot process. All Intel-based Macs have been using some version of
EFI as the boot firmware. At the time the platform debuted in 2006, it was in a stark contrast to PCs, which almost universally employed legacy
BIOS, and Apple's implementation of EFI did not initially implement the
Compatibility Support Module that would allow booting contemporary standard PC operating systems. Apple updated the firmware with CSM support with the release of
Boot Camp in April 2006, and since the release of
Windows 8 in 2012,
Microsoft has required its
OEM partners to use UEFI boot process on PCs, which made the differences smaller. However, Apple's version of EFI also includes some custom extensions that are utilized during regular macOS boot process, which include the following: • Drivers for the
HFS Plus and
APFS file systems with support locating the bootloader based on the "blessed directory" and "blessed file" properties of HFS+ and APFS volumes. The
EFI System Partition is thus not used or necessary for regular macOS boot process. • Other non-standard EFI services for managing various firmware features such as the computer's
NVRAM and boot arguments. Some of these differences can pose as obstacles both to
running macOS on non-Apple hardware and booting alternative operating systems on Mac computers – Apple only provides
drivers for its custom hardware for
macOS and
Microsoft Windows (as part of
Boot Camp); drivers for other operating systems such as
Linux need to be written by third parties, usually volunteer
free software enthusiasts. ==Digital rights management==