Motherboard Ports: What They Are and How They Work

Motherboard ports are the inputs or connection points where components plug into, including the rear ports at the back of a computer. 

If you’re replacing an internal hardware component or upgrading for better performance, you must remove the existing equipment from its dedicated motherboard port. To install new components, you do the opposite and plug the new component(s) into a dedicated port. 

There are also external ports located on the rear of the motherboard, for plugging in and disconnecting peripherals. Without opening the case, you can plug a mouse, keyboard, or external hard drive into the top or rear USB ports, for instance.

There are several types of internal ports including PCI-e, SATA, CPU, and so on. There are also external ports like USB, PS/2, RJ-45, and beyond. Both are referred to as ports.

What's Inside a Computer? What Plugs Into the Motherboard?

Inside a computer chassis or case is a collection of components, including a motherboard, CPU or processor, RAM, graphics card, and more. Collectively, these components make up a computer and are what allow it to run. The motherboard is the skeleton or frame that connects all of the individual components.

Motherboard ports are the various connection points where all of those components connect and plugin. For example, RAM slots are one type of port, usually located close to the CPU, and they are where you’d plug-in memory modules.

In short, all computer components plug into one of the motherboard ports, and the motherboard rests inside the chassis — what you may know as a computer tower.

What Ports Are on a Motherboard?

To make things a little easier, we’re going to separate the ports into two categories: Internal and external.

Internal vs. External Motherboard Ports: What's the Difference?

Internal ports are for the core components of a computer which reside inside the case. External ports are for peripherals and they reside outside the case, usually at the rear.

If you wanted to install an external hard drive by plugging it into a USB port, you would be using one of the external ports, generally located on the back of the motherboard which would be at the rear of the computer as you use it.

However, if you wanted to install an internal hard drive, including a solid-state drive, you would need to open the case and plug it into one of the internal ports on the motherboard. The same is true for expansion slots, where you might plug in something like a better graphics or additional RAM.

Laptops also have a motherboard inside, but due to their compact size you are usually limited by what you can upgrade or install.

Internal Motherboard Ports

Here are some of the most common internal ports on a modern motherboard:

1. CPU socket - Where the CPU or processor plugs in.
2. CPU power connector - Power cable connection for the CPU.
3. ATX power connector - Power cable connection for the system.
4. DIMM/RAM Memory slots - Connectors for system memory or RAM.
5. PCIe slots (x16, x2, x1) - Expansion card slots, including the graphics card.
6. M.2 connection - Solid-state drive connection.
7. SATA ports - Modern internal hard drive ports.
8. Front panel connector - Connection for USB, and audio ports on the front or top of the case.
9. Front panel header - Connection for LED/RGB lighting, power switch, and reset switch.
10. USB headers (3.1, 2. etc.) - Connection for rear USB ports on the motherboard.
11. CMOS battery - Bios battery for when there’s no system power.
12. Fan headers - Connection for the case and system fans.

There may be additional ports such as a COM/Serial header, TPM header, or RGB headers. Some ports will not be used, and sometimes there are redundant connections.

External Motherboard Ports (Rear Ports)

Here are some of the most common external ports on a modern motherboard:

1. PS/2 - Used for older PS/2 interface keyboards.
2. USB - Connection for USB peripherals including keyboards, mice, hard drives, audio equipment, and more.
3. HDMI/DisplayPort/VGA - They’re all video or display connectors to output video or audio to a monitor.
4. Ethernet /RJ-45 - Connection for wired internet.
5. Analog/Digital Audio - Connections for speakers and digital audio equipment, including home theater systems.

What Are the Types of Ports on a Motherboard?

There are a few different types of ports or connections on a motherboard you need to be aware of.

• Chipsets or sockets
• Main component connectors
• Expansion slots
• Rear ports

A CPU socket is where the processor is plugged in, while chipsets include pre-installed processing chips. They might be for audio, video, or hardware enhancements depending on the make and model of the motherboard. Some chipsets are designed to be compatible with only one of the major CPU manufacturers, like Intel vs. AMD.

The main component connectors are the primary ports on a motherboard, and they’re used for core components. Examples include RAM slots, SATA connectors, fan slots, and so on.

Expansion slots refer to the additional ports for plugging in extra hardware like graphics cards, solid-state drives, audio cards, and more.

The rear ports are all of the rear connectors used to plug in peripherals and external devices.

What Is a Motherboard Form Factor?

The form factor is basically the size of the motherboard, of which there are 3 main classifications. The largest is ATX, followed by micro-ATX, and finally mini-ATX.

The larger the motherboard, the more support it has for internal hardware and peripherals. ATX boards, for example, often include support for multiple graphics cards and expansion cards, whereas mini-ATX only supports 1 or 2. Larger boards have more ports.

The large boards, like ATX and micro-ATX motherboards, also require larger cases, or computer towers to accommodate both the bigger size and the added components that will be plugged into them.

What Is the Motherboard Chipset?

A motherboard chipset can mean a couple of things, like what additional hardware is supported. Typically, however, when someone refers to the chipset they are talking about the mainboard support or processor. Motherboards with AMD chipsets, for instance, are designed to work with AMD’s processors, while motherboards with Intel chipsets are designed to work with Intel’s processors.

With each type of chipset, there are different compatibilities, as both Intel and AMD have released a huge variety of processors to the market, and continue to do so.

How Do I Choose the Right Motherboard?

If you’re thinking about upgrading or installing a new motherboard, there are a few things you’ll need to decide first.

What type of processor do you want? If you go with AMD you’ll need to find an AMD-compatible motherboard with the appropriate CPU socket and chipsets. The opposite is true if you want an Intel processor.

What kind of expansion opportunities do you want? The more expansion slots available on the motherboard, the more components you can add later like a graphics card, sound card, or something else.

Do you want to use a solid-state drive? How many internal hard drives do you plan on installing? Make sure there are enough SATA ports and M.2 connectors for what you want.

Finally, how big or small do you want the computer to be? If you want something super compact, you’ll be looking at mini-ATX boards, which are also limited in terms of what you can install. They have fewer expansion slots and sometimes fewer rear ports.