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The Motherboard


The motherboard would have to be the most essential component of a computer. Often referred to as the mainboard, planar board or mobo the motherboard is a printed circuit board that contains all of the basic circuitry and components required for the computer to function. It provides a point of attachment for the CPU, add on cards, memory, hard disks and optical drives. It really is the core component that ties the whole machine together and allows these peripheral components to be able to talk to each other and function.

When you are shopping for computer parts it may be wise to select the processor that most suits your requirements and budget and then as the next step select a mother board that has the appropriate CPU socket for that processor. So as an example if I selected an Intel Core2 Duo processor I would then know that I require a socket 775 motherboard that has that processor on its supported CPU list. The Asus P5GC-MX pictured below supports this particular processor and is suitable for my requirements of a basic office machine. It has 2 DDR2 ram slots that will support up to 2gb of memory, double my my target 1gb for the machine and I know that I must buy DDR2 memory. It has 2 SATA ports and one IDE port which means that I can buy a suitable SATA hard disk drive and IDE DVD-RW optical drive. Because I have selected the mainboard and am aware of what slots and ports it has I can then confidently buy all of the peripherals I require knowing that they will connect to the mainboard without problems.

If you have any doubts ask the computer shop salesperson or in the instance of an online shop email them and clarify anything you are unclear on. This avoids purchasing incompatible components and makes your computer build less frustrating. Most computer retailers will have a number of common CPU/Motherboard combinations in stock and will be more than happy to guide you in your purchase as to what will work best with what.

Lets examine the P5GC-MX that I have purchased and see what slots and connectors it has.

Mainboard Connectors and Features Mainboard Rear Panel Connectors and Features
  1. CPU Socket This is where your central processing unit is installed.
  2. CPU Cooling fan power This connector is where the cooling fan for your CPU plugs in.
  3. Power Supply Connector This power connector is the main source of power for the mainboard.
  4. RAM slots These slots are where your memory is inserted.
  5. PCI Express X16 slot is used for video cards. Although this mainboard has on-board video usually add on video cards will outperform these for games, graphical programs etc.
  6. PCI Express X1 slot is usually used for add on cards such as video capture cards, wireless cards or aftermarket sound cards. This type of slot will eventually completely replace the PCI 2.2 slot.
  7. Primary IDE This is connected to IDE devices like Hard Disk Drives or CD/DVD drives. IDE is slowly beginning superceded by SATA. Some mainboards have a second IDE channel.
  8. SATA connectors Serial ATA (SATA) devices such as hard disk drives and CD/DVD drives plug in here. Some motherboards have up to eight of them.
  9. USB headers allow additional USB (Universal Serial Bus) ports to be connected to the mainboard. Some cases as an example have USB ports built into them and a cable is run to this header to make it work.
  10. Floppy Disk Connector This is where your floppy disk is plugged in.
  11. Front Panel Header The power button, reset switch, hdd light and power light all plug into this connector.
  12. PCI 2.2 Slots are used for add on cards such as wireless cards, video capture cards and other assorted peripherals. It is being superceded by PCI express.
  13. 4 Pin Auxillary Power provides additional power to the motherboard.
  14. PS2 Connectors Your keyboard and mouse can plug into these. The purple one is for the keyboard and the green one is for the mouse.
  15. 9 Pin Serial Port Is used for serial devices such as older mice or modems.
  16. Parallel Port is used for older scanners, printers and other parallel devices.
  17. VGA Port Not all mainboards have an onboard video adaptor but in this instance this mainboard does and it also has a PCI express x16 slot for a video adaptor. If the PCI express slot has a card inserted into it the onboard video is disabled.
  18. USB ports are destined to replace parallel and serial ports. They can take a wide variety of devices from printers and scanners to mice and cameras.
  19. LAN Port (RJ-45) allows the computer to connect to an ethernet local area network and interact with other computers and devices such as ADSL modems and network printers or shares.
  20. Onboard Sound Most motherboards have onboard sound cards that allow the machine to play music and sounds over a set of speakers. The light blue port is for Line-in, the line out port is green and the microphone port is pink.
  21. More USB ports Some motherboards have up to 10!