What is a Northbridge?

Alternatively called the PAC (PCI/AGP Controller) and nb, the Northbridge is an integrated circuit responsible for communications between the CPU interface, AGP, and the memory. Unlike the southbridge, the northbridge is directly connected to these components. It acts as a "bridge" for the southbridge chip to communicate with the CPU, RAM, and graphics controller. Today, the northbridge is a single-chip that is north of the PCI bus, however, early computers may have had up to three separate chips that made up the northbridge.

Below is a graphic illustration of the ASUS P5AD2-E motherboard and labels for each component of the motherboard, including the northbridge. As shown, the northbridge and southbridge commonly have a dedicated heat sink. Also, the northbridge is usually slightly larger than the southbridge, and is positioned closer to the CPU and memory.

When the CPU needs data from RAM, a request is sent to the northbridge memory controller. After the request is received, the northbridge responds with how long the processor needs to wait to read memory over the front-side bus. Some newer motherboards have replaced the northbridge and the southbridge with IHA.

My motherboard doesn't have a northbridge-

As manufacturers look for new ways to improve performance and reduce cost, they are moving functions of the northbridge chip to other CPU components including the southbridge. Beginning with the AMD64 AMD and the Intel Nehalem processors the memory controller was moved from the northbridge to the processor die. Later, the Intel "Sandy Bridge" and the AMD Accelerated Processing Unit processors placed all northbridge functions onto the CPU.

Standout-

Sometimes called a standoff and spacer, standouts are small metal or plastic screws that attach to a computer case and hold the motherboard in place. The picture helps give an example of a standout. In this picture, the left standout has a screw inserted in the hole to help demonstrate how it works. The motherboard would be placed between the standout and the screw.

Standouts also help keep a motherboard from touching the computer case. If the motherboard, specifically the solder points or other metal pieces touches the metal computer case, it can cause a short to occur in the motherboard. A short can cause the computer to not start up or it can cause damage to the motherboard. Using standouts is critical to prevent shorts from occurring and preventing damage to the motherboard.

Inserting a standout-

First, screw the standout into your computer chassis. With the standouts in place, place the motherboard on the standouts and insert the screw through the motherboard screw hole into the standout.

Sometimes called a standoff and spacer, standouts are small metal or plastic screws that attach to a computer case and hold the motherboard in place. The picture helps give an example of a standout. In this picture, the left standout has a screw inserted in the hole to help demonstrate how it works. The motherboard would be placed between the standout and the screw.

Standouts also help keep a motherboard from touching the computer case. If the motherboard, specifically the solder points or other metal pieces touches the metal computer case, it can cause a short to occur in the motherboard. A short can cause the computer to not start up or it can cause damage to the motherboard. Using standouts is critical to prevent shorts from occurring and preventing damage to the motherboard.

Inserting a standout-

First, screw the standout into your computer chassis. With the standouts in place, place the motherboard on the standouts and insert the screw through the motherboard screw hole into the standout. 

Motherboard mounting screw hole-

The picture shows an example of what a screw hole aka mounting hole would look like on the corner of a motherboard. Each motherboard has several holes to help hold the motherboard securely in place. Often the screw holes can be easily identified because they'll have metal surrounding each hole. Some earlier motherboards may also have holes without metal surrounding the hole. For these types of holes, the motherboard should have included a cardboard or paper washer to place between the screws and motherboard.

What is a Capacitor?

A capacitor is a component made of two or sets of two conductive plates with a thin insulator between them and wrapped in a ceramic and plastic container. When the capacitor receives a DC (direct current), a positive charge builds up on the plate (or set of plates) while a negative charge builds up on the other. This charge, which is measured in microfarads on a computer capacitor, remains in the capacitor until it is discharged. In the image, is an example of what a capacitor may look like on a computer motherboard.

Electrolytic capacitor on a computer motherboard-

Another common type of capacitor is an electrolytic capacitor, a higher capacitance capacitor in a smaller package. The picture to the bottom right is an example of these types of capacitors.

Like any other component in a computer, capacitors can fail, and when they do can cause the computer or the component to fail. When a motherboard capacitor fails the computer will no longer boot. Either the capacitor needs to be replaced or a new motherboard needs to be put in the computer.

The picture below is an example of an ABIT VP6 motherboard with blown capacitors and one example of how a capacitor may fail. Blown capacitors can be replaced, but for most users replacing the motherboard is often the easiest solution-  

Socket-

When referring to a processor, a CPU socket or processor socket is a connection that allows a computer processor to connect to a motherboard. For example, the Socket 370 is an example of such a socket. The picture shows an example of what a socket may look like on a motherboard. Although there were computers that used the slot processor, most computers today and in the past have used socket processors.

Why would I need to know the socket on my motherboard?

The processor socket helps determine what computer processors your computer motherboard can accept. For example, a socket 1 processor is not compatible with a Socket 370 because of the pin layout and the technology differences used in each socket.