PCIe cables are required to provide external power for our graphics card. These PCIe cables are usually equipped inside the Power Supply box.
Non-modular PSUs have attachable PCIe cables, while the modular & semi-modular PSUs come with detachable PCIe cables.
Some cheap power supply units doesnt have PCIe cables because these PSUs are not built to handle the load of power-hungry GPUs.
Expert PC builders always suggest checking the Power Supply spec sheet before buying to ensure the PSU has the necessary PCIe cables.
The PCIe cables come in different pin formats (6-pins, 6+2 pins, and 8-Pins). Check what connector type your graphics card will support, and then choose the Power Supply accordingly.
If you doesnt pick the Power Supply sincerely, you will end up buying the wrong power supply because some PSUs come with only 6-pin connectors, and some GPUs only accept 8-pin connectors. Read this article to check the compatibility factors between the graphics cards and the Power supply.
Below, I explained what PCIe connector type & how many cables your GPU needs, and what to do if your PSU doesn’t have sufficient PCIe cables.
How Many PCIe Cables Come With PSUs?
Modern power supplies mostly come between 2 – 4 PCIe cables depending on their design, form factor, and wattage capacity.
There is no accurate number about exactly how many PCIe cables come with the Power Supply. Still, according to our research, the 500W PSU mostly comes with 2 PCIe cables (sometimes higher), the PSU between 600W-700W comes with 3 PCIe cables, and the PSU above 750W comes with 4 PCIe cables.
Sometimes it is also seen that cheap Power Supplies with wattage under 450W doesnt included with any PCIe cables. So, if you have a power-hungry GPU, stop buying this type of Power Supply.
Different graphics cards require a different number of PCIe connectors and different pin formats. So you have to check what pin formats your GPU will need.
Some GPUs accept the 6-pin PCIe cable, while others accept the 8-pin cable, so you must buy a PSU that matches the connector type.
Let’s understand this by taking the examples of two GPUs-
The EVGA GeForce GTX 1650 GPU accepts a 6-pin PCIe cable, and for this graphics card, your power supply must have the 6-pin PCIe connector.
On the other hand, the EVGA GeForce GTX 1070 GPU only accepts the 8-pin cable, so your power supply must have the 8-pin PCIe connector.
Although most modern power supplies come with a 6+2 Pin PCIe cable, that’s why you won’t face any issues installing different GPUs based on connector type.
How Many PCIe Cables Do GPUs Need?
It depends on your graphics card. For example, some GPUs need one 6-pin or one 8-pin cable; some GPUs need two 8-pins, and the power-hungry GPUs require three 8-pin cables.
To determine precisely how many PCIe cables your GPU will require, you have to check the specifications of your graphics card.
Let’s understand why GPUs require different connector types and different numbers of PCIe cables in depth-
| PCIe Slot Motherboard | 6 Pin PCIe Cable | 8 Pin PCIe Cable | 12 Pin PCIe Cable |
| 75W | 75W | 150W | 600W |
The above table explains how graphics cards take power via the motherboard’s PCIe slot and via PCIe cables.
If your graphics card requires below 75W power, then it doesn’t need any PCIe cables; instead, it will take this power from the motherboard’s PCIe slot.
If your GPU requires between 75W to 140W power, then you need one 6-pin PCIe cable. In this case, the PCIe cable will supply 75W power, and the rest of the power the GPU will take from the motherboard’s slot.
If your GPU requires 150W power, then one 8-pin PCIe cable is needed for the GPU. Those graphics cards that require higher than 150w of power need multiple 8-pin PCIe cables.
For instance, the Nvidia RTX 3090 Ti graphics card requires 450W power and three 8-pin PCIe cables.
You can figure out how many PCIe cables your GPU need by checking the GPU specifications on Nvidia’s website or by searching the GPU model on Amazon.
I searched my GPU model on Amazon, and the image demonstrates that my MSI GeForce GTX 1660 Super GPU requires one 8-pin PCIe cable.
This is how you can easily figure out how many PCIe cables your graphics card will need.
PSUs Don’t Come With Enough PCIe Cables: What To Do?
Some unbranded power supplies do not have PCIe cables, and these PSUs are not built to handle power-hungry graphics cards.
If you have this type of PSU, then you can only install those GPUs that do not require external power via PCIe cables.
In some cases, the PCIe connector type of power supply does not match the GPU connector. For example, my MSI GeForce GTX 1660 Super GPU requires one 8-pin PCIe cable, and if I pick an unbranded PSU with only a 6-pin PCIe cable, then it won’t run with my system.
However, there are various types of PCIe adapters available in the market that we can use if our Power Supply doesnt have a sufficient number of PCIe cables.
While using these types of adapters, you have to be sure because these different adapters supply different power wattages. The SATA to PCIe supply 54W power, and the Molex to PCIe adapters supply between 54W to 60W power.
While the dual SATA to PCIe adapters can supply power up to 108 watts, read this complete guide to know which adapters you should use when your PSU doesnt have enough cables for GPUs.
Final Thoughts
This entire article explains that most modern PSUs come with PCIe cables, and how many cables you need depends on your GPU’s power requirement and design.
However, if your power supply lacks a sufficient number of PCIe cables, then you can use different types of adapters available in the market by checking the wattage.
