GPU Power Cable Guide [Basic Explanation of PCIe Connectors]

Most modern discrete graphics cards require additional power connectors for their high power consumption.

As the GFX cards are getting power-hungry day by day, you can see that most recent RTX 40 series cards require 16-pin connectors!

You may wonder what cables to use for the proper power supply to the GPU.

In this article, I will walk you through how PCIe power connectors work & what cables you need. Let’s dive in.

What are the PCIe Power Cables & How Many Do You Need?

Present-day Power Supply Unit (PSU) consists of many power connectors such as SATA data cables & power connectors, ATX-24 pin power connector, CPU power connector, PCIe cables, etc. Among these cables, PCIe power connectors are used to supply power to the GPU.

These PCIe power cables help the GPU to draw its required power to operate & provide the best performance. But how many PCIe cables do you require?

When picking a GPU for a PC, you should ensure that the PSU has enough PCIe power connectors to meet the demands of the card. Some older cards like GT 710 or GTX 1050 Ti don’t require an extra power connector, instead, the cards use PCIe x16 slot’s power.

But the PCIe x16 slot provides only 75W, which is nothing compared to the modern power-hungry cards, which can consume more than 600W. An RTX 3090 requires 3 x 8-Pin power connectors & if you install two RTX 3090, then you will need 6 x 8-Pin connectors.

So, the required PCIe cables depend entirely on your GPU specs & their power consumption. Now let me explain how many types of PCIe cables are used for the graphics cards.

Read more on can you use PCI-e cable for the CPU?

What Types of Power Connectors are Used for GPU?

As aforementioned, a motherboard’s PCIe x16 slot can provide up to 75W to the graphics card. Entry-level GPUs, that don’t require much power, typically get power through this slot & don’t need an additional power cable from the PSU.

Some of these GPUs are GT 710, GT 1030, GTX 1050, GTX 1050 Ti, GTX 1650, RX 460, RX 550, etc. These GPUs don’t need more than 75W for their processing & hence no power slot on the card.

Now, when you require additional PCIe power connectors, you may observe there are 6-pin cables, 8-pin or (6+2)-pin cables, & 12-pin cables.

Here are the power connector types GPUs are using:

1. 6-Pin PCIe Power Connector

Your mobo’s PCIe slot delivers up to 75W, but when a bit more power is needed, a 6-pin PCIe power connector is used in that case. This basic power cable allows the GPU to draw an additional 75W.

As low-tier to mid-tier GPUs don’t need more than 150W, with the help of a PCIe x16 slot & an additional 6-pin cable, the card satisfies its need.

You may also like to read about are PSU extension cables safe?

2. 8-Pin/ (6+2)-Pin Power Connector

While there is a fixed 8-pin connector, there is a variation of it that is the 6+2-pin connector. With the fixed 8-pin connector, it is limited to the 8-pin port of the GPU. So, you can’t utilize the connector for a 6-pin connector or with an 8+6-pin port GPU.

This 6+2-pin power connector comes in handy when the graphics card has one 8-pin & one 6-pin power connector slot. Additionally, this can also be used for the GPU with 8-pin.

However, as the 6-pin cable provides 75W, the 6+2-pin can cause confusion. Will this also provide 75W for having a 6-pin?

Well, no. The regular 8-pin cable supplies up to 150 watts. The 6+2-pin cable works like an 8-pin cable & similarly provides 150W.

So, with the combination of the PCIe x16 slot, the card can have up to 225 watts to power itself with an additional 8-pin cable. Moreover, if the card is more power-hungry and has an additional 6-pin slot along with an 8-pin, then it can draw up to 300W altogether. Not to mention, consuming this amount of power increases your GPU’s hotspot temp.

In addition, If the card has two 8-pin slots, in sum, the card can pull an extreme amount of power which is 375W. With the requirement of this hefty amount of power, ensure that you have enough wattage PSU to power the full computer.

3. 12-Pin Power Connector

The 12-pin power connector is a new addition to the PCIe power connector. Nvidia, for its RTX 3000 series graphics card, brought up this new power connector. With the same width as an 8-pin connector, this new 12-pin connector can supply up to 600W power!

As most power supplies don’t come with a 12-pin cable, Nvidia packaged their founder edition cards with an adapter. This adapter ensures compatibility with the extant PSU.

With this huge amount of power, if your PSU is not capable of meeting the requirement to supply enough power, your PC may not turn on for the power supply. Additionally, your PSU may get aged or may not have all the PCIe power connectors. So it is crucial to know when you need a new PSU.

These connectors are usually used for RTX 3090 Ti, RTX 4070 Ti, RTX 4080 & RTX 4090. Ensure to properly tighten & lock the cable with GPU & PSU side to avoid melting down the connector for a loose connection.

How Much Power Each PCIe Connector Provides

As a dedicated GPU needs to install on a PCIe x16 slot to work, it always gets 75W base power. Any additional power connector’s supplied amount is added with this 75W & thus we can calculate the total possible max power consumption.

For example, an additional 6-pin sums up the total power consumption (75W+75W)=150W. Similarly, for an additional 8-pin, it will be (75W+150W)=225W.

Here is a table of the GPU power cable guide containing PCIe cables with max possible consumption of power:

This table will clear many things for you at a glance. Now, if you lack any PCIe cables, what would you do? Is it safe to use converters in replace of a PCIe power cable? Continue reading to know about this.

You need to read our separate post on are PSU cables universal?

Should I Use Converters or Adapters for Powering GPU?

GPU power cable adapter is used when the PSU lacks enough or proper PCIe connector cables. When I had a Radeon 6870, it had two 6-pin PCIe slots. At that time, I had a Corsair CX 430 power supply, which had only one 6-pin power cable. A very bizarre situation.

I was unable to buy a new PSU, so as an option, I used a Molex to 6-pin converter to power up my GPU. But to be frank, this is not good & should not be used.

Similarly, you shouldn’t use a 6-pin to 8-pin connector. As a 6-pin is supposed to provide up to 75W, but as the GPU has an 8-pin & wants to draw 150W through the 6-pin converter, this results in overloaded & heats up the wire. In the end, this can create a fire hazard scenario.

However, you can use an 8-pin connector cable (divided into 6+2) to a 6-pin port GPU. Also, 8-pin daisy-chained connectors are also safe.

FAQs

How many power cables do you need for your GPU?

The requirement of total power cables depends on the graphics card. For the GTX 750 Ti, one single 6-pin cable is enough, whereas the RX 5700XT requires one 8-pin & one 6-pin power cable.

Why is the 16-Pin 12VHPWR getting melted?

If the 16-Pin 12VHPWR power connector gets loosened from any side (either GPU or PSU) of the connector port, it can get melted.

Should I use an adapter for powering the GPU?

I wouldn’t recommend using an adapter to power up a graphics card. Most of the adapters are made in China & are not quality. Besides that, the wire can heat up for overloaded power & can cause a fire hazard situation.

How to find out the PCIe cable?

Usually, the connectors are different & the cables are labeled with their respective slots. Though the CPU & GPU cable looks kind of similar, they won’t be interchanged.

Final Thought

In conclusion, all computer parts require cables connected to the PSU.

But, the cables are typically labeled for their specific parts. You will require a 6-pin or up to 12-pin PCIe cable for your beast graphics card.

In this article, I guided you on the GPU power cable. If you have any further queries, please leave a comment.