This introduction to the motherboard is fairly high-level in order to introduce various concepts to someone who isn't a complete tech-head. However, later sections will go into much greater detail. So if you already know all the stuff below, then please accept my apologies and move on to the deeper stuff.
The motherboard or mainboard is, in terms of area, probably the largest single component you will find in your typical box and is the silicon board that we plug various components into. It is the circuitry of this board that allows these components to communicate with each other.
|This is an image of an 'old' Slot 1 motherboard. In this case, 'Slot 1' is referring to the long brown slot near the top of the board, where one would plug in a Pentium II cartridge.|
The features you will find on a typical motherboard include:
- CPU socket / slot - where you plug your CPU.
- CPU voltage regulators - regulate power to the CPU, surprisingly.
- The 'chipset' (Northbridge/Southbridge) - supports all the rest of the hardware in your system.
- Memory sockets (aka memory banks)
- ROM BIOS - stores basic instructions that allow the computer's CPU to initialise. These instructions allow rudimentary hardware access, and store the CMOS/BIOS setup program.
- CMOS clock
- CMOS battery - maintains user settings.
- Bus slots - where other cards (e.g. graphics, modem) are plugged in.
The diagram below shows another Intel Pentium II motherboard. We can tell it is such a board from the type of CPU slot/socket that the motherboard uses (i.e. the slot or socket that the main CPU plugs into). In this case, it is a 'Slot 1' motherboard. The shape and size of this slot or socket is dependent on the type of CPU the motherboard was designed for. For example, the older square 'Socket 7' supports chips such as the Intel Pentium, Cyrix 6x86 and the AMD K6 series. Slot 1 motherboards support Pentium II and Celeron chips. Slot A motherboards support the original AMD Athlon chips while Socket A motherboards support the improved Athlon Thunderbird chip. More details about CPU architectures and their slot/socket requirements can be found in the CPU Guru section.
The diagram shows several types of connectivity that you may find on a motherboard. Indeed, this single diagram alone essentially shows you how to build your own PC, given the right parts of course! For example, modern graphics cards would be plugged into the brown AGP slot. Memory is plugged into the DIMM banks as shown. The interfaces labelled as IDE1 and IDE2 are designed for IDE devices such as hard drives, CDROM drives, DVD drives and CD writers.
Level of Integration
Note that some motherboards are referred to as integrated, which means that one or more additional peripheral devices (such as sound cards, modems, graphics adaptors, and network cards) are built into the motherboard. The advantage of this arrangement is a cheap overall solution. However, the major disadvantage is that such a motherboard is not so easily upgraded (with respect to a particular peripheral device). While an integrated device (such as a sound card) can usually be disabled in the system BIOS to make way for a better 'plug-in' card (such as a PCI sound card), integrated boards usually (due to a lack of space) have fewer expansion bus slots. This said, these days it's very rare to come across a motherboard that isn't 'integrated' to some degree. Most motherboards usually come with integrated (aka on-board) sound, although a connaisseur (whether it be some who likes their mp3s or a gamer) would usually opt to disable it and plug in a better sound device. For example, on-board sound (at this time of writing) is unlikely to be Dolby 5.1 compatible, while any decent sound card would be.
Choosing the right motherboard can be tricky. It's worth considering which integrated devices would be desirable. For example, for a home network any on-board Ethernet adaptor would probably be sufficient. Similarly, if you want a dial-up modem (which is rapidly being replaced by Broadband solutions), an on-board 56K modem will probably be as good as any card you could buy. The one to avoid at all costs (unless you never plan to upgrade) is on-board graphics, given that graphics cards evolve very rapidly, as do the demands of modern games.
Another consideration is RAID (Redundant Array of Independent/Inexpensive Disks), technology that provides 'redundancy' to your hard disk setup. The main reason for using RAID is for resilience: data is duplicated over more than one drive so that if one fails, you will not lose your data. Many modern boards come with an on-board implementation of RAID.
A very important consideration for a user who wants to get the most speed out of their system is the chipset. This is a set of chips (no, really!) that essentially governs how all the components in your system interact, like a system 'control centre'. To get the most out of your hardware, you need to have a good chipset. For example, some chipsets are aimed at high-end users who may want to overclock their systems - running their system at a faster rate than the hardware is recommended for. So, if speed is your primary goal, then it really is worth reading up on the various chipsets and reading reviews of the latest motherboards. Yes, it sounds sad, but it will be worth it (and could save you from potential problems and upgradability blocks). Visit the chipset section for more information.
Example - the EPoX 8K5A2+ Athlon board
The image below is a picture of the EPoX motherboard of the Athlon 2000+ system I used to have. You can see that it has 6 PCI slots (more than enough), one AGP4X slot, and no ISA slots. This is as it should be, since ISA is now ancient history. It has 3 DIMM slots, supporting up to PC2700-specification 333MHz DDR RAM (more on this in the memory section, allowing up to 3Gb of memory! Some people complain that this board has only 3 DIMM slots. Do any of these people actually need more than 3Gb of memory?
If you look closely, you may be able to make out the 'VIA' written on a chip towards the centre of the board, next to the PCI slots. This is the VIA Southbridge component (a VT8235) of the chipset which handles I/O integration. It's interesting to note that the KT333 Northbridge - the chipset component that handles high bandwidth activity, such as communication with memory and the AGP subsystem -actually has it's own heatsink. This just goes to show the complexity of modern chipset designs. Many chipsets now require heatsink and fan assemblies, just like the CPU!
You can also see four IDE/ATA interfaces. Two of these are standard ATA-133 interfaces (blue) while the other two (red) are ATA-133 RAID compliant interfaces that use the on-board Highpoint HPT372 RAID Controller.
Other useful features on this board include an onboard LAN interface (for networking), a USB2 controller (to allow the use of external USB2 or USB1.1 devices; for more information, check out the Comms Intefaces section), and a two-digit LED readout for diagnosing potential motherboard problems.
Last, but not least, the motherboard BIOS allows easy manipulation of just about everything you could possibly want to configure. For example, overclocking is made easy by the fact that you can manually adjust the system clock speed.
If you're looking for a high-performing Athlon-based system, you can't go far wrong with a motherboard like this.
Well, that's it for the motherboard intro. Let's move on and have a brief look at the CPU.
|Just Too Good
Last updated: June, 2006 (DJL)