NVIDIA SLI: What it is and How to Set it Up

By Jonny Lin in Technical Tips Tags: NVIDIASLIWindows

Perhaps, as an NVIDIA video card users, you want to use more than one cards on your computer to push its graphics power to a new level. You may have heard of a term, a technology called “SLI” that can help you. But you may not have a clear idea of what it is and how it can boost your machine performance yet.

But don’t worry. If you are looking for a detailed guide on SLI, you’ve come to the right place. The following of this article will show you in detail what SLI is and how you can set it up on your computer. Check it out now!


What is SLI?

SLI stands for Scalable Link Interface. It is a technology developed by NVIDIA which allows its users to use two, three or four video cards on one single computer. This technology connects all the video cards together and combines them into one video output. With SLI, computer performance can be boosted to varying degrees, but in some cases users can get 100% of power from each of the GPUs (Graphics Processing Unit). 

All video cards under an SLI system share the rendering information in the same environment. To organize all these GPUs, SLI uses a rendering mode called Alternate Frame Rendering (AFR). Basically, it means each GPU renders one of N frames respectively (“N” here represents how many cards you use). This is designed to enable every GPU to work independently and maximize the power of an SLI system.


How to set up SLI?

The process of installing multiple NVIDIA video cards and configuring SLI is not very complicated. It is similar to install a single video card. But there are still a few things you need to pay attention. The following are the steps of installation:

1. Check SLI compatibility of your computer

The first thing you should do before SLI setup is to make clear whether your graphics cards, motherboard, CPU and RAM, power supply, etc. support SLI.

Video cards:

In fact, NOT ALL models of NVIDIA video card support SLI. There are several ways to identify an SLI-supported video card:

The following is a list of GPU that can be used to build an SLI system. If your graphics cards have a GPU that is included in the list, congratulations, your video card is well qualified!

Note that this list contains only the most recent and commonly-used GPUs that support the SLI feature. You may need to try the methods as follows or do some research on the Internet to find out more about the SLI compatibility of your GPU.
Some of the GPUs supported
TITAN XpGTX 1080 TiGTX 980 TiGTX 780 TiGTX 690GTX 590GTX 480
GTX TITAN XGTX 1080GTX 980GTX 770GTX 680GTX 580GTX 470
GTX TITAN ZGTX 1070 TiGTX 970GTX 760 TiGTX 670GTX 570GTX 465
GTX TITAN BlackGTX 1070GTX 960GTX 760GTX 660 TiGTX 560 TiGTX 460
GTX 650 Ti BOOSTGTX 550 Ti

Method 2: Check your video card box. If there is something like “SLI Ready” on the box, your card supports SLI.

Method 3: Check if there is an SLI connector on the top edge (next to the metal panel) of your video card. If so, your video card is ready for SLI.

Location of SLI connector
IMPORTANT! You can ONLY use IDENTICAL video cards to set up an SLI system. They have to have the SAME brand, model, and specifications.


To use SLI, your motherboard also has to support this functionality. A motherboard is certified by NVIDIA as supporting SLI has an “SLI Ready” certification. You can check the box that contained your motherboard or the manual for this certification. Or you can go to its official website and view detailed information on your motherboard compatibility with SLI.

CPU and memory:

An SLI system can remarkably improve performance. With that said, the graphics power can still be bottlenecked by your CPU and computer memory. In order for your SLI configuration to release its full power, it is suggested that you use a powerful CPU (Intel i7 processor or equivalent recommended) and increase your computer memory (8 GB or above recommended).

Power supply:

A powerful video card requires a huge amount of electric power, let alone multiple ones. You should carefully calculate the amount of power your machine needs before building an SLI system, and change your power supply when necessary.

When everything is ready, then it’s time to go on to the installation part.

2. Install your video cards

To installing multiple video cards:

1) Turn off your computer and unplug the power cable from it.

2) Remove the cover of your computer case.

3) Remove the slot covers corresponding to PCI-Express x16 slots you are using on the back of your computer case.

PCI-Express x16 slots

4) Plug the video cards into the PCI-Express x16 slots, starting from the primary slot (the closest one to the CPU)

5) Connect your video cards with an SLI bridge connector that come with your motherboard or you got from NVIDIA. (Connect the bridge to the SLI connectors on the top edge of your video cards.)

An NVIDIA SLI bridge connector

6) Connect the power connectors (8-pin) from your power supply to your video cards.

Location of 8-pin power connector on a video card

7) Reinstall the covers of your computer case and reconnect all the cables to your system.

8) Turn your computer on.

3. Configure SLI on your Windows system

The final step is to install or update your graphics driver and then enable SLI on your NVIDIA Control Panel.

Install graphics driver:

Your video cards need a driver so as to run on your computer. And your SLI system won’t be able to run smoothly if your graphics driver is wrong or out of date. You should install the latest graphics driver on your computer. If you want to do it easily and automatically, you can use Driver Easy.

Driver Easy will automatically recognize your system and find the correct drivers for it. You don’t need to know exactly what system your computer is running, you don’t need to risk downloading and installing the wrong driver, and you don’t need to worry about making a mistake when installing.

You can update your drivers automatically with either the FREE or the Pro version of Driver Easy. But with the Pro version it takes just 2 steps (and you get full support and a 30-day money back guarantee):

1) Download and install Driver Easy.

2) Run Driver Easy and click the Scan Now button. Driver Easy will then scan your computer and detect any problem drivers.

3) Click the Update button next to your graphics driver to automatically download and install the correct version of this driver (you can do this with the FREE version). Or click Update All to automatically download and install the correct version of all the drivers that are missing or out of date on your system (this requires the Pro version – you’ll be prompted to upgrade when you click Update All).

Enable SLI

You can enable your SLI on NVIDIA Control Panel that comes with the NVIDIA graphics driver. To do so:

1) On your Windows, right-click an empty area of the desktop. A context menu will occur. Then click NVIDIA Control Panel

2) Click Configure SLI, Surround, PhysX in the left pane. Then click the option button of Maximize 3D performance. (You can select other options if you are using multiple monitors. But make sure Disable SLI is not selected)

Click the option button of Disable SLI if you want to turn off your SLI system.

Now your SLI system is ready. Enjoy the superpower it brings to your computer!