To Make Comparative Study on Motherboards

Basic HardwareTo Make Comparative Study on

Motherboards

MOTHERBOARD

A motherboard (sometimes alternatively known as the Mainboard, mobo (abbreviation), MB (abbreviation), system board, logic board) is a printed circuit board (PCB) found in many modern computers which holds many of the crucial components of the system, such as the central processing unit (CPU) and memory, and provides connectors for other peripherals.

Motherboard specifically refers to a PCB with expansion capability. The term mainboard is applied to devices with a single board and no additional expansions or capability. In modern terms this would include controlling boards in televisions, washing machines and other embedded systems.

The motherboard serves to connect all of the parts of a computer together. The CPU, memory, hard drives, optical drives, card, sound and other ports and expansion cards all connect to the motherboard directly or via cables. The Motherboard can be thought of as the “Back Bone” of the Computer.

Important Motherboard Facts: Motherboards, cases and power supplies all come in different sizes called form factors. All three must be compatible to work properly together. Motherboards vary greatly in respect to the types of components they support. For example, each motherboard supports a single type of CPU and a short list of memory types.

Additionally, some video cards, hard drives and other peripherals may not be compatible. The motherboard manufacturer should provide clear guidance on component compatibilities.

Popular Motherboard Manufacturers: ASUS, AOpen, Intel, ABIT, MSI, Gigabyte, Biostar

Motherboard Description: The motherboard is mounted inside the case, opposite the most easily accessible side. It is securely attached via small screws through pre-drilled holes.

The front of the motherboard contains ports that all of the internal components connect to. A single socket/slot houses the CPU. Multiple slots allow for one or more memory modules to be attached. Other ports reside on the motherboard which allows the floppy drive, hard drive and optical drive to connect via ribbon cables. Small wires from the front of the computer case connect to the motherboard to allow the power, reset and LED lights to function. Power from the power supply is delivered to the motherboard by use of a specially designed port.

Also on the front of the motherboard are a number of peripheral card slots. These slots are where most video cards, sound cards and other expansion cards are connected to the motherboard.

On the left side of the motherboard (the side that faces the back end of the case) are a number of ports. These ports allow most of the computer's external peripherals to connect such as the monitor, printer, keyboard, mouse, speakers, phone line, network cable and more. Most motherboards also include USB and FireWire ports here that allow compatible devices to connect to your computer when you need them - devices like digital still and video cameras.

The motherboard and case are designed so that when peripheral cards are used, the sides of the cards fit just outside the back end, making their ports available for use.

HISTORY

Prior to the advent of the microprocessor, a computer was usually built in a card-cage case or mainframe with components connected by a backplane consisting of a set of slots themselves connected with wires; in very old designs the wires were discrete connections between card connector pins, but printed circuit boards soon became the standard practice. The Central Processing Unit, memory and peripherals were housed on individual printed circuit boards which plugged into the back plate.

During the late 1980s and 1990s, it became economical to move an increasing number of peripheral functions onto the motherboard. In the late 1980s, motherboards began to include single ICs (called Super I/O chips) capable of supporting a set of low-speed peripherals: keyboard, mouse, floppy disk drive, serial ports, and parallel ports. By the late 1990s, many personal computer motherboards supported a full range of audio, video, storage, and networking functions without the need for any expansion cards at all; higher-

end systems for 3D gaming and computer graphics typically retained only the graphics card as a separate component.

The early pioneers of motherboard manufacturing were Micronics, Mylex, AMI, DTK, Hauppauge, Orchid Technology, Elitegroup, DFI, and a number of Taiwan-based manufacturers.

The most popular computers such as the Apple II and IBM PC had published schematic diagrams and other documentation which permitted rapid reverse-engineering and third-party replacement motherboards. Usually intended for building new computers compatible with the exemplars, many motherboards offered additional performance or other features and were used to upgrade the manufacturer's original equipment.

DESIGN

The Octek Jaguar V motherboard from 1993 This board has few onboard peripherals, as evidenced by the 6 slots provided for ISA cards and the lack of other built-in external interface connectors

A motherboard provides the electrical connections by which the other components of the system communicate. Unlike a backplane, it also connects the central processing unit and hosts other subsystems and devices.

A typical desktop computer has its microprocessor, main memory, and other essential components connected to the motherboard. Other components such as external storage, controllers for video display and sound, and peripheral devices may be attached to the motherboard as plug-in cards or via cables, in modern computers it is increasingly common to integrate some of these peripherals into the motherboard itself.

An important component of a motherboard is the microprocessor's supporting chipset, which provides the supporting interfaces between the CPU and the various buses and external components. This chipset determines, to an extent, the features and capabilities of the motherboard.

Modern motherboards include, at a minimum:

Sockets (or slots) in which one or more microprocessors may be installed. In the case of CPUs in BGA packages, such as the VIA C3, the CPU is directly soldered to the motherboard.

Slots into which the system's main memory is to be installed (typically in the form of DIMM modules containing DRAM chips)

A chipset which forms an interface between the CPU's front-side bus, main memory, and peripheral buses

Non-volatile memory chips (usually Flash ROM in modern motherboards) containing the system's firmware or BIOS

A clock generator which produces the system clock signal to synchronize the various components

Slots for expansion cards (these interface to the system via the buses supported by the chipset)

Power connectors, which receive electrical power from the computer power supply and distribute it to the CPU, chipset, main memory, and expansion cards. As of 2007, some graphics cards (e.g. GeForce 8 and Radeon R600) require more power than the motherboard can provide, and thus dedicated connectors have been introduced to attach them directly to the power supply. Most disk drives also connect to the power supply via dedicated connectors.

Additionally, nearly all motherboards include logic and connectors to support commonly used input devices, such as PS/2 connectors for a mouse and keyboard. Early personal computers such as the Apple II or IBM PC included only this minimal peripheral support on the motherboard. Occasionally video interface hardware was also integrated into the motherboard; for example, on the Apple II and rarely on IBM-compatible computers such as the IBM PC Jr. Additional peripherals such as disk controllers and serial ports were provided as expansion cards.

Given the high thermal design power of high-speed computer CPUs and components, modern motherboards nearly always include heat sinks and mounting points for fans to dissipate excess heat.

CPU SOCKETS

A CPU socket or slot is an electrical component that attaches to a printed circuit board (PCB) and is designed to house a CPU (also called a microprocessor). It is a special type of integrated circuit socket designed for very high pin counts. A CPU socket provides many functions, including a physical structure to support the CPU, support for a heat sink, facilitating replacement (as well as reducing cost), and most importantly, forming an electrical interface both with the CPU and the PCB. CPU sockets on the motherboard can most often be found in most desktop and server computers (laptops typically use surface

mount CPUs), particularly those based on the Intel x86 architecture. A CPU socket type and motherboard chipset must support the CPU series and speed.

INTEGRATED PERIPHERALS

Block diagram of a modern motherboard, which supports many on-board peripheral functions as well as several expansion slots

With the steadily declining costs and size of integrated circuits, it is now possible to include support for many peripherals on the motherboard. By combining many functions on one PCB, the physical size and total cost of the system may be reduced; highly integrated motherboards are thus especially popular in small form factor and budget computers.

For example, the ECS RS485M-M,[4] a typical modern budget motherboard for computers based on AMD processors, has on-board support for a very large range of peripherals:

Disk controllers for a floppy disk drive, up to 2 PATA drives, and up to 6 SATA drives (including RAID 0/1 support)

integrated graphics controller supporting 2D and 3D graphics, with VGA and TV output integrated sound card supporting 8-channel (7.1) audio and S/PDIF output Fast Ethernet network controller for 10/100 Mbit networking

USB 2.0 controller supporting up to 12 USB ports IrDA controller for infrared data communication (e.g. with an IrDA-enabled cellular

phone or printer) Temperature, voltage, and fan-speed sensors that allow software to monitor the

health of computer components.

Expansion cards to support all of these functions would have cost hundreds of dollars even a decade ago; however, as of April 2007 such highly integrated motherboards are available for as little as $30 in the US.

PERIPHERAL CARD SLOTS

A typical motherboard of 2009 will have a different number of connections depending on its standard.

A standard ATX motherboard will typically have one PCI-E 16x connection for a graphics card, two conventional PCI slots for various expansion cards, and one PCI-E 1x (which will eventually supersede PCI). A standard EATX motherboard will have one PCI-Express 16x connection for a graphics card, and a varying number of PCI and PCI-E 1x slots. It can sometimes also have a PCI-E 4x slot. (This varies between brands and models.)

Some motherboards have two PCI-E 16x slots, to allow more than 2 monitors without special hardware, or use a special graphics technology called SLI(for Nvidia) and Crossfire (for ATI). These allow 2 graphics cards to be linked together, to allow better performance in intensive graphical computing tasks, such as gaming, video editing etc.

As of 2007, virtually all motherboards come with at least four USB ports on the rear, with at least 2 connections on the board internally for wiring additional front ports that may be built into the computer case. Ethernet is also included. This is a standard networking cable for connecting the computer to a network or a modem. A sound chip is always included on the motherboard, to allow sound output without the need for any extra components. This allows computers to be far more multimedia-based than before. Some motherboards contain video outputs on the back panel for integrated graphics solutions (either embedded in the motherboard, or combined with the microprocessor, such as the Intel HD Graphics). A separate card may still be used.

TEMPERATURE AND RELIABILITY

Motherboards are generally air cooled with heat sinks often mounted on larger chips, such as the Northbridge, in modern motherboards. Insufficient or improper cooling can cause damage to the internal components of the computer and cause it to crash. Passive cooling, or a single fan mounted on the power supply, was sufficient for many desktop computer CPUs until the late 1990s; since then, most have required CPU fans mounted on their heat sinks, due to rising clock speeds and power consumption. Most motherboards have connectors for additional case fans as well. Newer motherboards have integrated temperature sensors to detect motherboard and CPU temperatures, and controllable fan connectors which the BIOS or operating system can use to regulate fan speed. Some

computers (which typically have high-performance microprocessors, large amounts of RAM, and high-performance video cards) use a water-cooling system instead of many fans.

Some small form factor computers and home theatre PCs designed for quiet and energy-efficient operation boast fan-less designs. This typically requires the use of a low-power CPU, as well as careful layout of the motherboard and other components to allow for heat sink placement.

A 2003 study found that some spurious computer crashes and general reliability issues, ranging from screen image distortions to I/O read/write errors, can be attributed not to software or peripheral hardware but to aging capacitors on PC motherboards. Ultimately this was shown to be the result of a faulty electrolyte formulation, an issue termed capacitor plague.

Motherboards use electrolytic capacitors to filter the DC power distributed around the board. These capacitors age at a temperature-dependent rate, as their water based electrolytes slowly evaporate. This can lead to loss of capacitance and subsequent motherboard malfunctions due to voltage instabilities. While most capacitors are rated for 2000 hours of operation at 105 °C(221 °F), their expected design life roughly doubles for every 10 °C (50 °F) below this. At 45 °C (113 °F) a lifetime of 15 years can be expected. This appears reasonable for a computer motherboard. However, many manufacturers have delivered substandard capacitors, which significantly reduce life expectancy. Inadequate case cooling and elevated temperatures easily exacerbate this problem. It is possible, but tedious and time-consuming, to find and replace failed capacitors on PC motherboards.

FORM FACTOR

Motherboards are produced in a variety of sizes and shapes called computer form factor, some of which are specific to individual computer manufacturers. However, the motherboards used in IBM-compatible systems are designed to fit various case sizes. As of 2007, most desktop computer motherboards use the ATX standard form factor — even those found in Macintosh and Sun computers, which have not been built from commodity components. A case's motherboard and PSU form factor must all match, though some smaller form factor motherboards of the same family will fit larger cases. For example, an ATX case will usually accommodate a microATX motherboard.

Laptop computers generally use highly integrated, miniaturized and customized motherboards. This is one of the reasons that laptop computers are difficult to upgrade and expensive to repair. Often the failure of one laptop component requires the replacement of the entire motherboard, which is usually more expensive than a desktop motherboard due to the large number of integrated components.

BOOTSTRAPPING USING THE BIOS

Motherboards contain some non-volatile memory to initialize the system and load an operating system from some external peripheral device. Microcomputers such as the Apple II and IBM PC used ROM chips, mounted in sockets on the motherboard. At power-up, the central processor would load its program counter with the address of the boot ROM and start executing ROM instructions. These instructions displayed system information on the screen, ran memory checks, and then loaded an operating system from an external or peripheral device (disk drive). If none was available, then the computer would perform tasks from other memory stores or display an error message, depending on the model and design of the computer and version of the BIOS.

Most modern motherboard designs use a BIOS, stored in an EEPROM chip soldered or socketed to the motherboard, to bootstrap an operating system. When power is first applied to the motherboard, the BIOS firmware tests and configures memory, circuitry, and peripherals. This Power-On Self Test (POST) may include testing some of the following things:

Video adapter Cards inserted into slots, such as conventional PCI Floppy drive Thermistors, voltages, and fan speeds for hardware monitoring CMOS used to store BIOS setup configuration keyboard and mouse network controller Optical drives: CD-ROM or DVD-ROM SCSI hard drive IDE, EIDE, or SATA hard disk Security devices, such as a fingerprint reader or the state of a latch switch to detect

intrusion USB devices, such as a memory storage device

On recent motherboards, the BIOS may also patch the central processor microcode if the BIOS detects that the installed CPU is one in for which errata has been published.

Asus P5Q-VM

Asus Rampage III Extreme

Intel DQ35JO

Comparison b/w Asus P5Q-VM, Asus Rampage III EXTREME & Intel DQ35JO

CPU ASUS P5Q-VM

ASUS Rampage III EXTREME

Intel DQ35JO

CPU Type Intel Core2 Extreme/Core

2 Quad/ Core2

Duo/Pentium dual-core/Cel

eron dual-core /Celeron

Core i7 Processor Extreme Edition

/Core i7 Processor

Core2 Quad / Core2 Extreme

/ Core2 Duo

Socket Type

LGA 775 Socket 1366 LGA 775

Form Micro ATX ATX Micro ATX

Factor

Chipset

Northbridge

Intel G45 Intel Q35

Memory Support

Memory Standard

DDR2 1066 / 800 / 667

MHz

DDR3 2200(O.C.)/2133(O.C.)/2000(O.C.)/1800(O.C.)/

1600/1333/1066 Non-ECC

DDR2 800

Memory Slots

4x240pin 6 x DIMM 4�240pin

Max. Memory

16GB 24 GB 8GB

Dual Channel Support

Expansion Slots

PCI Express 2.0 x16 1

PCI Express 2.0 x1 2 2

PCI Slots 1 1

Storage

SATA 3 Gb/s ports 6 6 6

SATA RAID -- 0/1/5/10 Matrix RAID

Onboard Devices

Onboard Audio Chipset

Realtek ALC1200

--

Onboard LAN Chipset Realtek 8111C Gigabit Intel

Intel 82566DM

Onboard USB 6 x USB 2.0 6 x USB 2.0

Audio Channels 8 8 4

Rear Panel Ports

PS/2 1

USB 6 x USB 2.0 6 x USB 2.0

S/PDIF Out -- 1