What Is a Motherboard? – Part One

June 6, 2012 under Computer Components

So you are ready to start buying your computer hardware to build your first computer. That is great. Your journey to learn computer hardware basics starts with the board that births all other circuit boards, or something similar to that. If you have no motherboard, you have no computer. The type you choose directly dictates the other hardware you will be getting for your computer. So what is a motherboard, and what are some of its characteristics? The following information will explain what a motherboard(or system board or mainboard) is and the major parts it has, in general. Due to this topic's complexity, it will be divided into multiple posts.

The motherboard physically connects all other components, thus allowing a computer to run as a whole. It is usually located either at the side or the bottom of a computer case. Of course, how a system board fits in a case is very important. That is why you will want to make sure what case you are getting conforms to the size of your board.

System board form factors are classified as ATX, BTX, or NLX(the major ones used today). ATX boards are most popular today. They are designed to run cooler and allow full-length expansion cards to be installed. Micro ATX boards can work with normal-sized ATX and smaller ATX cases. They are similar in design to their bigger sibling, just smaller. Of course, with less surface space, they have less space for memory, expansion cards, integrated components, etc. Also, they are designed to require less energy, using smaller power supplies. So, adding USB peripherals(which use energy from the computer if they do not have there own power adapter), can eventually stress out the power supply. NLX boards are mainly used for more horizontal computer cases. Expansion cards are placed on sideways expansion slots. Therefore, expansion cards sit parallel to the motherboard. Finally, BTX motherboards were released a few years ago. They allow for better cooling using passive heat sinks. This also allows for a quieter system, as less fans are needed.

So what are the major parts of a motherboard? Here is a list below with a quick description of each.

  • Chipset - Circuits integrated to the motherboard using a Northbridge and Southbridge(data paths) to allow the CPU to communicate between the system board and other components.
  • Expansion slots – These are ports where you install components to the mainboard, like video cards, network cards, RAM, etc. These use buses to communicate with the CPU.
  • Power connectors – These feed power into internal components from the power supply.
  • Disk Drive Connectors – These connect the hard drive and other disk drives to your the mainboard
  • Keyboard connector – These connects a keyboard to your computer.
  • Peripheral ports – These connect peripherals, such as a game controller or microphone.
  • BIOS – This is firmware(a type of software) used to run a test(POST) to make sure components are working. It then starts the boot processor of your computer until your operating system takes over. It has an interface where you can change important settings for your computers components, among other things.
  • CMOS battery – This allows the BIOS to always have power running to it, even when the computer is off.  This is so CMOS memory can store user settings and specified component parameters for the BIOS.
  • Jumpers, DIP switches – These are used to allow the correct electrical voltage to transfer to the computer hardware on the motherboard.
  • Firmware – This is software that is actually encoded into computer hardware that can be run without instructions from an operating system. The BIOS uses this type of software to run before an operating system, such as Windows, starts.

Describing in detail the components of a motherboard is out of the scope of this post. However, we will start trying to tackle that in part two of "What Makes a Motherboard?" in a future post. In any case, this is a good start to understanding what a system board is and what it is made up of. Continue researching so that you may take your computer hardware basics knowledge to new heights!