What is a motherboard?
A motherboard is the main printed circuit board (PCB) in a
computer. The motherboard is a computer's central communications backbone
connectivity point, through which all components and external peripherals
connect.
Motherboards can be found in virtually all computers,
especially desktop and laptop PCs. The components that connect through them
include chipsets, central processing units (CPU) and memory. The external
peripherals include Wi-Fi, Ethernet and graphics cards with the graphics
processing unit, or GPU.
Motherboard manufacturers include Acer, ASRock, Asus,
Gigabyte Technology, Intel and Micro-Star International.
How do motherboards work?
The PCB of a large motherboard may include six to 14 layers
of fiberglass, copper connecting traces and copper planes for power and signal
isolation. Other components get added to a motherboard through expansion slots.
These include processor sockets; dual in-line memory modules; Peripheral
Component Interconnect (PCI), PCI Express (PCIe) and solid-state drive M.2
slots; as well as power supply connections.
A heatsink and fan manage the heat components such as the
CPU generate. Typically motherboards offer additional connectivity through
a Southbridge chip such as PCI, Serial Advanced Technology Attachment
or SATA, Thunderbolt, USB and other interfaces.
The CPU is generally connected to double data rate 3 (DDR3),
DDR4, DDR5 or onboard LPDDRx RAM and PCIe. This is done through
point-to-point interconnects such as HyperTransport, Intel's QuickPath
Interconnect and Ultra Path Interconnect. Choosing a motherboard often
determines many features a computer will support.
Motherboard designs in desktop computers typically are the
ATX motherboard, which is Intel's improved version of IBM's AT design. Other
form factor designers include the following:
1.
Extended ATX
2.
Mini-ATX
3.
Micro ATX
4.
BTX
5.
Micro BTX
6.
Mini-ITX
7.
Micro ITX
8.
Nano-ITX
Some memory controllers are now built into CPUs; that has
eliminated the Northbridge chips that provided memory management from
the motherboard. Integrated video has moved from a motherboard slotted
peripheral to graphics-enabled CPUs.
AMD's Ryzen has a system-on-a-chip design that
also makes the Southbridge chipset optional. This CPU integration has
cut motherboard manufacturers' costs. They can offer base systems for
workstations and entry-level computers and can design customized
implementations for various processors that enable platform upgrades.
Gaming motherboards are made for high-performance computers;
they are more powerful and have more features than motherboards for desktop and
laptop computers.
Motherboard components
Each motherboard is designed to support specific components,
such as CPUs and memory. They can accommodate most types of hard drives and
peripherals.
Motherboards include the following primary components:
·
CPU with its logic circuitry that
processes the instructions from programs, the operating system and other
computer components;
·
Memory where instructions and data
are temporarily stored and executed;
·
Storage interface for
solid-state or hard disk drive for persistent data and application storage;
·
ROM BIOS providing
non-volatile memory that stores firmware, such as the basic input/output system
or BIOS;
·
Northbridge chipset that
connects CPU, memory, storage and other components;
·
Southbridge chipset that
connects peripheral elements to the motherboard and connects to the
Northbridge;
·
Cooling fans that maintain a
suitable internal operating temperature;
·
Peripheral connector slots for
plugin peripheral cards, such as graphics and communications adapters;
·
Connectors for peripheral devices such
as USB ports and other connectors for external devices;
·
The backup battery that ensures key
system configuration data is maintained when main power is unavailable; and
·
The power connector, conecting to an
external power source.
Many other elements comprise a typical motherboard. Think of
a motherboard as a large mosaic of electrical connections linking the various
parts of a computer.
