Computer Power Connectors – CompTIA A+ 220-901 – 1.8

Every device in our computer needs power, and there are many different ways to get the right voltages to the right component. In this video, you’ll learn about SATA power, Molex connectors, ATX 12 volt connectors, EPS 12 V power, PCI Express power interfaces, and the primary motherboard power connectors.

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If you were to look at a normal power supply that might go in your computer, you might see a number of different kinds of connectors on it. In this video, we’re going to step through what all of these connectors might be and where you might plug them in on your motherboard. Our storage devices these days tend to be static connected devices. And you’ll see on the back of the storage device that there’s a connection for data and then a larger 15 pin connector for power.

This is the 15 pin SATA connection. It includes voltages for 3.3 volts, 5 volts, and 12 volts, although 3.3 volts is rarely used by these devices. As you can see, it’s a very specific type and it’s only going to fit into that SATA connection. A more generic power connector might be something like this Molex connector. There’s one created by the Molex connector company, although there’s other types made by other companies. Amp, for instance, makes the same connector called a MATE-N-LOK. And this will provide both 12 volts and 5 volts of power on a connection.

It’s very common to see the Molex connector used for many different components. You can plug it into storage devices, fans that are inside of your computer case, optical drives, and other peripherals as well. One connector you’ll see on older motherboards might be this four pin ATX 12 volt connector. This is called an ATX 12 V advanced technology extended motherboard connector. This provided some additional 12 volt power for these older motherboards, especially for powering the CPU.

These connectors might be labeled ATX V12. They might say P4 on the side of them. Or they might have the CPU marked on the edge of the connector. And they are keyed very specifically for the connector on the motherboard. If you’re plugging in a 4 pin connector and it’s not going into the connection, you may have the wrong connector for that motherboard. Another CPU power connector type is the 8 pin EPS 12 volt power connection. This is also called the EPS 12 V cable. It stand for the entry level power supply specification.

You often see this provided from the power supply as what they call a 4 plus 4 connection, which means it has an ATX 12 volt four pin connection on one side that you can combine together to create the eight pin EPS 12 volt power. This power connection was created to provide additional power, especially on systems that had multiple CPUs and needed the additional power for the processors themselves.

This is 8 pins or 8 connectors, but this is not the same as a PCI express 8 pin connector. Those are two completely different kinds. And they are keyed differently. So you won’t be able to plug the 8 pin EPS into an 8 pin PCI express. Here’s a good picture of the 4 plus 4 functionality. You’ve got the 4 pin that you would use for the ATX 12 volt. Or you can combine this together to make it an 8 pin EPS 12 volt connector.

You’ll occasionally add an expansion card to your computer. And the expansion card needs additional power. So for those cases, we have the PCI express 6 pin and 8 pin power connectors. The 6 pin power connector is a 75 watt connector. And the 8 pin power connector provides 150 watts of 12 volt power. It’s very common to see these 6 or 8 pin power connectors on PCI express adapters like video cards. Video cards have very powerful CPUs and need a lot of energy to be able to run them.

Some cables will have a 6 or 8 pin modular connection. There’s really two pieces so that you can use the same connector to plug into a 6 pin, or you can combine them together to plug into an 8 pin connection. The connector that brings power from your power supply to the main motherboard power is probably the largest power connector that you’ll see on the motherboard. This is providing 3.3 volts, 5 volts, and 12 volts of power to the motherboard. And you may see 20 pin connectors, or 24 pin connectors.

The 20 pin connector was the original one from the ATX standard. But when we added PCI express, we needed additional power for the motherboard. So those motherboards will have 24 pin connectors. If you have an older motherboard, but a newer power supply, you can still use that 24 pin connector on the power supply and plug-in to the 20 in motherboard. It’s designed to be backwards compatible with those motherboard types. And connecting it is very easy. There’s really only one way it can connect because each one of these power connectors is keyed a particular way.

It should be relatively easy to find the main motherboard power. It’s a relatively large connector. And you can see it’s a similar type of connection coming from the power supply inside of your computer. The two connectors should fit perfectly together. And if they aren’t, you may have it turned around the wrong direction. It should be sliding in very easily into this main motherboard connection. And when you finally get it all the way down it should snap into place. They usually have a lock on the sides that you can’t accidentally pull that power off of the motherboard.