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SLI Bridge Not Detected? [Reasons Why & Ways to Fix]

Creating the perfect computer setup – whether for graphics/editing, gaming, or something else entirely – largely comes down to personal preference. Each person has their own desired specs or things that matter more to them than others. But the simple fact is that each component has to work compatibly with the others.

An SLI bridge works to connect two of the same graphics cards together. The bridge relays data from one to the other directly.

If your computer says that the SLI bridge is not detected, it could be that the power supply isn’t providing enough power, the motherboard isn’t providing enough power, your video card or bridge is improperly seated, or the bridge is not properly enabled for your motherboard. To fix, troubleshoot to pinpoint the exact issue. 

What is an SLI Bridge?

The SLI bridge is the Scalable Link Interface bridge. Basically, the SLI is a small circuit board that comes packaged with motherboards that are SLI-ready. That is an important distinction as not every motherboard is capable of handling an SLI bridge.

The bridge comes with connectors at each end. They attach to the top most connectors on video cards that are SLI-ready. Basically, the board bridges two different video cards for increased performance and capacity. The bridge joins two identical video cards together in order to exchange information when the SLI configuration is enabled.

What Would an SLI Bridge be Used for?

So, what would you use an SLI bridge for? SLI bridges are used to send data between two identical graphics cards directly while also reducing bandwidth constraints. An SLI bridge is generally not needed if you have a single GPU that can handle your needs.

But if you have, say, a pair of x8 speed GPUs, there may be benefit in bridging the two. It all depends on your setup and needs. The more components in the mix, the greater the likelihood that a component could fail and cause issues with the rest of the setup.

Reasons the SLI Bridge Might Not be Detected

When you get a “bridge not detected” message – the verbiage can be different depending on manufacturer – there are more than a few reasons. The error may tell you to remove graphics cards that are not compatible with your SLI, for instance.

There are as many as a dozen reasons why your SLI bridge isn’t being detected. Let’s run through the different potential issues.

Legacy Motherboard Lacks Proper Support

Your motherboard is one of the most crucial pieces to ensuring that your SLI bridge works. The motherboard is the hub for all the other components. If it is not compatible with one of the components, that component won’t work as it is supposed to.

If your legacy motherboard doesn’t have a proper jumper setting enabled, it won’t be able to support two graphics cards while in SLI mode. Make sure that the manufacturer of your motherboard has details on how to properly enable SLI mode to recognize the jumper.

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SLI Mode is Not Enabled

It might go without saying, but you can’t just slap a bridge on your dual graphics cards and expect it to work. If the SLI bridge is even detected, it won’t work the way that it was meant to work. Which is why we need to go to the BIOS first.

Depending on what your system is, the BIOS may not have the term “SLI” listed. It could be PCI or something related to PCI like PCI express. Check with your manufacturer to see what BIOS settings that they use.

When you are certain, you can go into the BIOS and enable the SLI. This will allow the SLI bridge to be properly detected, so that it can start relaying information between the two graphics cards.

Daughterboard

There are some motherboards out there that require the configuration of a daughtercard. These are other boards that are wired into either the motherboard or another separate board. These are meant to work to enable support for the pair of graphics cards.

Make sure to check the manual from the manufacturer first. Depending on the model and manufacturer, you may be able to get away without a daughterboard being introduced.

Lack of Power from the Motherboard

The role of the motherboard – of them, anyway – is to provide the necessary power to the various components that it supports. If your SLI bridge is not being recognized, there is a possible that the motherboard is not providing ample power to the graphics cards.

For example, most motherboards have a 4-pin power connector that is located near the SLI/PCI slot. This is the dedicated power source for those slots so the integrity of the power signal can be preserved. If your motherboard lacks those pins, then it may not have the capability of supporting the power supply for the graphics cards.

SLI Connector is Seated Improperly

With any computer component, it has to be seated properly in order to function properly. If you SLI bridge is showing as not detected, check to see if it is seated on the graphics cards properly. Without that direct connection, the SLI bridge won’t be detected.

The simplest course of action is to disconnect and then reconnect the bridge to the cards. If you can’t find the connector on your graphics cards, try contacting the motherboard vendor to get one. And depending on what graphics card you use they may not support the use of an SLI connector.

Inadequate Power Supply

There is the chance that the power supply you are using is not up to the task of properly powering each of the components, like a dual graphics card setup. If you have a basic SLI setup, a 450-Watt power supply should do fine.

The more complex you get, the more complex configuration you will need. If you have high-end graphics cards, you will need a more comprehensive power supply to accommodate. Check out the different power recommendations for SLI bridges online before you make your purchase. You should be able to find a list of qualified motherboards, too. Remember that you have to be able to power these superior graphics cards, they don’t just plug into any motherboard.

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What are the Benefits of Using SLI?

Knowing the various issues that could lead to your SLI bridge not being detected, we should ask ourselves if they are worth it in the first place. There are some obvious perks to using dual graphics cards, but it is not all sunshine and roses.

Better Graphic Quality

One of the biggest benefits to using dual graphics cards with an SLI bridge is improved image quality without having to sacrifice graphical fidelity. When talking about the latter, it is basically everything that makes for a beautiful gaming experience like frame rate, resolution, and detail.

Not only that, but if you happen to run a higher refresh rate than what your monitor allows, having an SLI can come in handy. It lets you have playable frame rates while also increasing the overall fidelity of the graphics.

Better Performance

Perhaps the biggest benefit of going with an SLI bridge is that it has a better overall performance. That is, if you are going at a resolution above 1080p (4k or 8k), specifically. Otherwise, an SLI bridge won’t make a dramatic difference.

For gaming, high-resolution monitors are quite common, meaning they have a larger refresh rate. All of this means greater demand on the GPU to render those frames and pixels. Going with a dual setup connected by a bridge means being able to not only meet those maxed settings, but doing so smoothly.

Playing games that have high resolution settings (4k, 5k, 8k, and 16k) need an SLI to improve performance. Besides, having a higher refresh rate like 144Hz and above means having the supporting technology to get the most out of those increased specs.

They Look Cool

Let’s face facts: part of what makes gaming setups so awesome is that they are just visually appealing. And if you want to make your gaming setup look as cool as possible, it has to have dual graphics cards and an SLI to go with it.

There are obviously better incentives to go with the dual card setup, but enjoying the improved aesthetic certainly doesn’t hurt anything.

With SLI Bridge Issues the Simplest Explanation is Often Times the Right One

If you are getting a message that your SLI is not being detected, start simple. The simplest explanation is often times the right one. The more complex you get in terms of solutions, the more likely there is going to be further issue.

Start by checking to see if the bridge is properly seated. This is the issue more often than not. If that isn’t the cause, then make sure that your motherboard is compatible with the bridge that you use. You can’t just plug and play with random manufacturers.

Past that, it may be time to upgrade motherboards. Some may not meet the power requirements needed to support dual graphics cards in the first place. When in doubt, consult the manufacturer.

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