An often overlooked yet critical factor when building a PC is power consumption. A top-of-the-line graphics card can place too great a burden on many PSUs and that is something gamers need to avoid. To help you better understand GPU power connectors, we have prepared this guide.
Some low-end and mid-range graphics cards can only use the PCI Express x16 slot as a power source, but more demanding cards will need to use 6-pin or 8-pin PCI Express power connectors.
This can be particularly confusing when using a multi-GPU setup, as 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 feature multiple PCI Express x16 slots in order to connect more GPUs but, as previously mentioned, this increases the power requirement.
Here are a few examples of GPUs that don’t require any external power: GT 1030, GTX 1050 2GB variant, RX 550, RX 460, and many others. As none of these GPUs have a lot of processing power, they don’t need more than 75 watts of power.
This connector can supply the GPU with an additional 75 watts of energy. This means the graphics card will use the PCI Express x16 slot and also draw power directly from the PSU (Power Supply Unit).
Despite the fact that 150 watts are enough for most graphics cards, high-end cards such as NVIDIA’s RTX 3080 require more than 320 watts and system power of 750 watts. As 150 watts will be enough for most mid-range cards, these usually feature 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 might not seem right when compared to the 6-pin connector, the 8-pin connector can deliver 150 watts to a graphics card. If the GPU requires more than 150 watts, it will come with an 8-pin connector or two 6-pin connectors.
As always, there are exceptions. The most power-hungry graphics cards will come with a 6-pin and an 8-pin connector. For example, NVIDIA’s GeForce RTX 3060 has both types of connectors. As a result, it has a maximum power consumption of 170 watts.
There are even some exceptional cases where the GPU will have two 8-pin connectors. By simply adding the numbers together, we get a total of 375 watts, but that is an extreme amount. In addition, you still need to power the CPU (which is another big energy consumer) and the rest of your PC’s components.
In even rarer cases, there are enthusiast GPUs that require three 8-pin connectors. These are usually the manufacturers’ highest-end models made to provide the best possible cooling and overclocking. An example of such a GPU is the GeForce RTX 2080 Ti LIGHTNING Z.
In any case, it’s safe to say that your machine will be properly powered with a good 650 watts PSU. However, if you’re building a gaming rig with an RTX 3080/3090 or if you want to future-proof it (which is almost impossible), you should choose a more powerful PSU. 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 case-by-case basis.
With the release of NVIDIA’s RTX 3000 series, we were introduced to 12-pin power connectors. This move was made out of necessity as NVIDIA desperately needed the extra power for their most powerful cards and came up with a rather elegant solution.
A 12-pin connector is roughly the same size as an 8-pin connector, but it can draw a lot more power. NVIDIA was forthcoming regarding the availability of PSUs with 12-pin connectors, so it released an adapter that 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. Fortunately, computers are made by engineers who like to modify hardware that isn’t suited to their needs by default.
A company called Molex pioneered these pin connectors all the way back in the late 50s and early 60s and it has since become synonymous with the term. Don’t be surprised if you hear these being referred to as Molex Adapters or Molex Converters.
4-Pin Molex to 6-Pin PCI-E Adapter Cable
You should use this cable if your graphics card requires a 6-pin power connector but your PSU doesn’t have it. This is usually a sign of a very old PSU, so it might be time for an upgrade. If you’re determined to keep your existing PSU, know that this sort of adapter sometimes requires one 4-pin connector, but it will 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 them to an 8-pin connector. 4-pin to 8-pin is something that will likely be 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 were relatively few PSUs with a 12-pin power connector on the launch of the 3000 series, NVIDIA included a dual 8-pin to 12-pin adapter with its product.
SATA to 6-Pin PCI-E Adapter Cable
This cable converts your SATA connectors to a 6-pin connector, but this is generally advised against. There is a chance that SATA won’t be able to handle the power that your graphics card requires and this is not something that you want to encounter, especially if the cable is labeled as “SATA only“.
SATA to 8-Pin PCI-E Adapter Cable
SATA can also be adapted to an 8-pin power connector. In this 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 older PSUs weren’t built with current power requirements in mind. If possible, it’s best to use Molex to Molex for your GPU needs, as they have thicker wires and can transfer more current. A SATA to Molex adapter could be exposed and lead to burnout if the GPU draws more power with a higher load or by overclocking.