What is PCIE power cable? Explained.

PCIe power cables are used to power a GPU (graphics processing unit) or other card requiring electrical power. Not all GPUs require PCIe power cables, but those that need one do not work without a PCIe cable. So what is PCIe power cable? How does it look? And what to do if you do not have one or the number of cables isn’t enough for your GPU.

What PCIe power cable looks like?

what PCIE power cable looks like

Picture of the PCIe power cable going out from PSU (power supply unit) to GPU, which is connected to PCIe slot and requires a lot of power.

Types of PCIE power cables

What is a 6 pin PCIe power cable?

6 pin PCIe power cable

75 W power will pass through the PCIe 6 pin power cable in the most common cause. Keep in mind that your PCIe x16 slot also has 75 watts. 

With one 6 pin PCIe cable, you should get about 150 w of power to your GPU. That’s not a small amount, but today’s video cards like the GTX 3060 (TDP 170 W) or 3080 (TDP 350 W) require much more power than 150 watts.

What is a 8 pin PCIe power cable?

8 pin PCIe power cable

An 8 pin PCIe power cable can provide up to 150 W. This is twice the size of a 6 pin PCIe power cable. So if you have GTX 3080, which requires 350 W, you will need to use 2x 8 pin PCIe power cables. (150 W + 150 W + 75 W (from PCIe slot) = 375 W).

What are PCIe Cables used for?

It is used to power up GPU or other devices connected to the PCIe slot.

What to do if you do not have PCIe cable?

molex female conector

Older PC sometimes does not have PCIe cables. In this case, you can buy a Molex to PCIe power cable adapter. Most old computers have a lot of Molex connectors that can be made into PCIe power connectors.

how to conect molex to pcie adapter

Keep in mind that Molex connectors are rated for 54 watts. So if you connect 2 Molex to 1 PCIe power cable 6 pin, it will be safe enough. If you need an 8 pin PCIe power cable, you need to do calculations and check your GPU TDP and how many watts you need.

For example, the PCIe slot gives you 75 w, 8 pin PCIe power cable (made from Molex) will give you around 100 w, so you already have 175 w. If your GPU requires 200 w, do not risk using Molex adapters.

If you want to buy a Molex to PCIe adapter, you can buy it from Amazon here. Always remember that these kinds of adapters are a temporary solution.

Dual 4 Pin Molex to 6 Pin PCI Express Power Cable

An 8-Pin PCIe to Molex (2X)

How many PCIe Cables do I need?

It depends on the equipment you have. You may not need a PCIe power cable. For example, if you have GTX 1050 Ti 4 GB GPU, you may do not need any PCIe power cable because this GPU uses only 75 W.

But if you have GPU, like Radeon HD 7970 X2, it has a listed TDP of 500 W, which requires 3 x of PCIe 8 pin power connectors (150 W + 150 W + 150 W + 75 W= 525 W.

Missing Modular PCIe Cables

Be careful when buying cables for PSU. In most cases, different cables from different brands are not interchangeable.

If you decide to buy, be sure to find the exact model of PSU and only then buy cables for it.

Conclusion

The PCIe power cable is a cable that provides additional power to the device connected to the PCIe slot. You need to know that the PCIe slot itself has 75 watts, the 6 pin PCIe cable also has 75 watts, and the 8 pin PCIe cable powers up to 150 watts.

If you have more questions, please write them in the comment section below. We will try to answer them as soon as possible.

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