Beware of spending money on a second graphics card before you check if your setup can support it. Most graphics cards require motherboard support for SLI (or CrossFire) to work. You can easily check whether your motherboard supports SLI by looking at its product page online or checking out this extensive list of SLI-ready motherboards on Nvidia’s website.
Do AMD Motherboards Support SLI?
Despite having its own version called CrossFire, many AMD motherboards have also supported SLI. You’ll notice that I used the past tense there because Nvidia has more or less abandoned the whole SLI concept. Nvidia stopped releasing new SLI driver profiles for graphics cards after January 2021.
That means new AMD graphics cards won’t offer support for SLI either. There is somewhat of a silver lining for multi-GPU enthusiasts though. Instead of relying on motherboard support, some AAA games will implement SLI support natively from now on—the catch being that it’s only a handful of them.
Can Every Motherboard Fit Two or More Graphics Cards?
Most motherboards can support more than one GPU. It mainly depends on how many PCIe x16 slots your motherboard has, as that’s where you’ll plug in your GPUs. Although, keep in mind that some motherboards have more PCIe x16 slots available than the amount of GPUs they can support.
Your best bet is to check out a motherboard’s product page on its manufacturer’s website. It should tell you how many graphics cards it can support.
Considering 3-Way or 4-Way SLI? Here’s Why it Won’t Work
Once upon a time, people were doing all sorts of interesting things with their setups, including using 3-way (tri-SLI) and even 4-way (quad-SLI) configurations. This meant they used a bridge connector to add a third and fourth GPU to their motherboard to create super rigs.
The problem is, while it looks cool and your friends will undoubtedly be envious, this type of setup likely won’t increase performance. The best benefit you’ll get from this type of setup is less strain on your GPUs as the load will be distributed among them. So it’s pointless to go this route unless you’re running 3 old GPUs that can’t handle your graphics load individually.
The other major snag here is that, while you can still technically get 3-way or 4-way SLI with older hardware, Nvidia has stopped supporting it entirely. So you’ll be working with outdated software as well. That’s not the greatest option all things considered unless you already have old parts lying around and can’t afford a newer GPU card and motherboard.
Now for the final nail in the multi-GPU coffin—it’s extremely complex to set this up. Even if you manage to get everything going, you’ll most likely run into multiple snags once you start up any game. This old comment from Promit, an ex-Nvidia employee, shines a bleak light on just how much multi-GPU setups often broke games during the development process.
SLI Requires Motherboard Support to Work
Before you head off and buy more graphics cards, keep in mind that your motherboard should support SLI. There are a few GPU cards that don’t require motherboard support, like the dual graphics cards (GeForce GTX 690 and GeForce GTX TITAN Z) from Nvidia. Motherboards consider them a single unit card because they occupy the same PCIe x16 slot.
How To Check if Your Motherboard Supports SLI
If you already have the motherboard, you can just check its box or the motherboard itself. Let’s use this Fatalty Z170 Gaming K6 motherboard as an example.
If you take a look at the list of logos on the front of the box, you’ll see one of them says SLI. The motherboard itself also has a sticker with the SLI logo on it right there next to the PCIe x16 slots. You might have to zoom in a bit to see them.
Have a specific list of motherboards in mind? Then you’re better off just checking their store pages or product pages for SLI support instead. The product page on the manufacturer’s website should list pretty much everything you could want to know about the motherboard, including whether it has SLI support.
What to Do if Your Motherboard Doesn’t Support SLI
If your motherboard doesn’t natively support SLI, then I‘m afraid you’re out of luck. Unless you’re willing to buy one that does. The truth is, these days it’s far more economical to just buy one good graphics card than to struggle with stringing multiple less powerful GPUs together anyway.
There are a few “hacks” going around the web that claim you can trick your motherboard into supporting SLI. I wouldn’t recommend testing them out and messing with your BIOS or Hardware, unless you really know what you’re doing. Unfortunately, inserting two GPUs and simply slapping a bridge connector on the slots isn’t going to work either.