An often overlooked yet vital factor when building a PC is power consumption. A top-of-the-line graphics card can significantly overbear the PSU and that is something gamers certainly do not want. To better understand GPU power connectors, we have prepared this resource for you.
Some low-end and lower-tier mid-range graphics cards can only use the PCI Express x16 slot to draw their power from, but more demanding ones will need to use 6-pin or 8-pin PCI Express power connectors. This can be particularly confusing when using a multi-GPU setup, like with the SLI. In that case, the power requirement is the sum of two (or more) connected graphics cards.
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PCI Express x16 Connector
Motherboards come with the aforementioned PCI Express x16 slot that can provide a maximum of 75 watts of power. Some come with multiple PCI Express x16 slots in order to connect more GPUs, but like we’ve already said, this increases the required power.
This connector can supply the GPU with an additional 75 watts of energy. What this means is that the graphics card will use PCI Express x16 slot and also draw power directly from the PSU (Power Supply Unit).
Despite the fact that 150 watts is enough for most graphics cards, cards like Nvidia’s RTX 2080 require more than 220 watts and system power of 650 watts. Since 150 watts will be enough for most mid-range cards, these usually come with the 6-pin power connector.
The terms “PCI Express cables” or “PEG cables” (for PCI Express Graphics) can also be used to describe 6-pin connectors.
Although the math doesn’t seem right when compared to the 6-pin connector, the 8-pin connector can deliver 150 watts to the graphics card. If the GPU requires more than 150 watts, it will, by design, come with an 8-pin connector or two 6-pin connectors.
As always, there are outliers. The most power-hungry graphics cards will come with a 6-pin and an 8-pin connector. For example, Nvidia’s GeForce GTX 1080 Ti has both types of connectors. As a result, it has a maximum power consumption of 250 watts.
There are even some outlandish situations where the GPU will have two 8-pin connectors. So, by simply adding all the numbers together, we get a total of 375 watts, but that is truly an extreme case. On top of that, you still need to power the CPU (which is another big energy spender) and the rest of the components.
It’s safe to say that your machine will be properly powered with a decent 650 watts PSU, although if you’re building a gaming rig and want to future proof it (which, let’s be honest, is nearly impossible), you can get a more powerful PSU. But be careful because with great power comes a greater risk of overheating.
There is also a rule of thumb that the PSU runs best when it’s at 50% capacity, but that is a different topic that should be looked at on a per-case basis.
With the release of Nvidia’s RTX 3000 series, we were introduced to 12-pin power connectors. This was a move out of necessity as Nvidia really needed the extra power for their all-powerful cards and they actually came up with a rather elegant solution.
A 12-pin connector is roughly the size of an 8-pin connector, although it can logically draw a lot more power. Nvidia was forthcoming in regard to the availability of PSUs with 12-pin connectors, so it released an adaptor which allows two 6-pin connectors to interface with its card’s 12-pin slot.
Adapters Or Converters For Connectors
There are often compatibility issues when building a PC and power connectors are no different. Luckily, computers are made by engineers who like to modify stuff that’s not fitted to their needs by default.
A company by the name of Molex pioneered these pin connectors all the way back in the late 50s and early 60s, and has since become synonymous with the term. So don’t be surprised to hear these referred to as Molex Adapters or Molex Converters.
4-Pin Molex to 6-Pin PCI-E Adapter Cable
You’ll want to use this cable if your graphics card requires a 6-pin power connector but your PSU doesn’t have it. That’ll actually be a sign of a very old PSU, so maybe it’s time for an upgrade. If you’ll still stick to your guns, know that this sort of adapter can sometimes require one 4-pin connector, but it’ll most often be two, which is the recommended option.
4-Pin Molex to 8-Pin PCI-E Power Adapter Cable
This cable uses two 4-pin connectors and adapts it to an 8-pin connector. 4-pin to 8-pin is something that will likely be most useful with upper mid-range and high-end graphics cards.
6-Pin to 8-Pin PCI-E Adapter Cable
If you’ve recently purchased a top-class GPU, it will likely require an 8-pin connector, which some PSUs might not have. In that case, the 6-pin to 8-pin adapter is the solution for you.
2x 8-Pin To 12-Pin PCI-E Adapter Cable
As mentioned earlier, the 12-pin power connector is the latest technology necessary for Nvidia’s 3000 series graphics cards. Because there was a relatively small supply of PSUs with a 12-pin power connector upon the launch of the 3000 series, Nvidia included a dual 8-pin to 12-pin adapter with its packing.
SATA to 6-Pin PCI-E Adapter Cable
This cable converts your SATA connectors to a 6-pin one, but this is generally advised against. It’s possible that SATA won’t be able to handle the power that your graphics card may require and this situation is not something that you want to be in the middle of, especially if the cable is labeled as “SATA only“.
SATA to 8-Pin PCI-E Adapter Cable
Likewise, SATA can also be adapted to an 8-pin power connector. In this particular scenario, there will be two SATA connectors for one 8-pin connector.
Important Note About Adapters
In most cases, it’s best to upgrade your PSU if you lack connectors, as it might be the case that they weren’t built with your power consumption in mind. If possible, it’s best to use Molex to Molex for your GPU needs, as they have thicker wires and can offer more current. A SATA to Molex adapter might be exposed and lead to burnout if the GPU draws more power with a higher load or by overclocking.