 A few weeks ago, I was sitting in my office reading through a white paper from Nvidia in order to make a video for you guys that would simplify and answer all the crazy questions people had about the new multi-GPU and SLI configurations for the 1000 series and DirectX 12 era. Armed with the white paper, I thought this would be an easy task, but within an hour or two, I was collapsed onto my desk contemplating the sheer futility of life. Since then, I have received answers to my multiple, horrendously long emails to Nvidia, ones that hopefully will allow me to shed some light on what the hell is going on. Cooler Master's MasterCase Maker 5 features their Freeform Modular System, which allows you to customize, adjust, and upgrade. Make it yours at the link in the video description down below. First things first, the question that has been hotly debated since the keynote where they announced the GTX 1080 and 1070 is 3 and 4-way SLI still a thing? No, not for gaming, only specifically overclocking and benchmarking applications like Fire Strike, Catzilla, etc. That's it. I'm not even upset. I like this move. 3 and 4-way SLI are and have been always such an unjustifiable configuration that telling people very directly not to do it and going even further by not supporting it contributes nothing to Nvidia's bottom line and saves people from lighting their money on fire. Good guy Nvidia. But all of that said, and this adds a lot of confusion to the topic, you can still play games with 3 or 4 graphics cards. And you can use the performance of all of them together, just not in classic SLI mode. This can be done with MDA mode, also known as Multi Display Adapter mode, or through LDA Explicit, also known as Link Display Adapter Explicit mode, two different methods of GPU cooperation that are at least somewhat separate from LDA Implicit mode, which is what Nvidia will be using for SLI. What? Okay, I'll get more into those specifics later. It's not that bad. But here we go. Basically, game designers can explicitly code any degree of multi GPU support for their games, including 3 and 4-way Nvidia solutions. But please note that because this responsibility lies with the developers, don't expect it to happen much. Back to the modes. Which one is best out of the three? Great question. And I can confidently tell you that we don't know yet. I don't have enough stuff to test. And in asking Nvidia, their official response was that they don't have enough data yet and they need more DX12 multi GPU enabled games. Notice that part about developers probably not doing it much. In order to make any sort of qualitative determination, which also means that no, there will be no benchmarks in this video. That will come later. But I do have many more interesting things to say. So I would, I would, I would stay. So here's what we do know. Nvidia's new high bandwidth SLI bridge is not required. You do need it for 5K gaming and surround gaming. But if you have one of those fancy LED bridges, you're fine for 4K gaming and 2560 by 1440p gaming at 120 hertz. And you have a standard bridge. You can take another step down and do 2560 by 1440p at 60 hertz and 1920 by 1080 gaming. Nvidia will automatically notify you that your bridge is not good enough if you try to push it to a setup that is outside of those specifications. So I wouldn't worry about it much. Plug everything in, see if it works. If it does, you're good. If it doesn't, they'll tell you and you can fix it pretty easily. But Luke, you lie. They were saying things about enthusiast key that would allow us to unlock three and four way stuff. That software unlock does not exist. Nvidia killed it. That was fast. And given how clear I've made my position on the merits of greater than two way SLI, it should come as no surprise that I think it's a good thing. But I also didn't buy three or four graphics cards already based on a promise that Nvidia made that they would all work together with this thing called enthusiast key. I feel like that while a number of customers were impacted by this is probably fairly low. These individuals would represent the most die hard of the die hard Nvidia fans and gaming enthusiasts. And they should probably have it made up to them in some way. Just saying. All right, but hold up. Let's take a few steps back. How exactly does this MDA and LDA mode thing work? Well, when SLI is disabled in the Nvidia control panel, your cards will be running in MDA mode. MDA is Microsoft allowing any set of GPUs to be used, including cross brand. So theoretically, you can use an AMD card and an Nvidia card and have them be all over the place in terms of tiers and stuff. And it should work. You can do this all at the same time. DirectX 12 new feature named shared fences allows for the synchronized commands to the various GPUs and said GPUs will be able to share a pool of memory, which resides in system memory. All that kind of stuff is cool. When SLI is enabled, however, your setup will be in LDA mode, another Microsoft technology. The sub mode LDA implicit allows you to use the SLI bridge to transfer display data between GPUs without interference caused from other agents activity on PCI E and should through this clearer communication method allow for additional capabilities by utilizing the bridge. But we'll have to wait and see what the impact is of that while in LDA mode. If the games are coded to support explicit multi GPU, they will be able to scale. However, well with the amount of cards you have in the system without using the SLI bridge again, we'll have to wait to see how well this works. But this would theoretically allow you more than two cards. And that's basically all we have to work with at the moment. We will have to wait and see how MDA and LDA explicit modes handle regular two way operation compared to traditional SLI and what the three and four way situation ends up looking like. So here's the final word. If you want to play games with your setup and aren't interested in just rerunning the same freaking benchmarking programs on the same freaking setup all day, you should probably stick with a maximum of two cards. And which mode works best will be heavily dependent on the game or application you're using. Oh, and I guess you could run to an SLI and a third for physics. If you just really hate your money, you can do that. 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If you just thought that scene was cool and hit the dislike button, I won't hold it against you. That's fine. If you want to jump on the forum to discuss everything I said on here and argue about things please argue like in a friendly way. Discuss if you want to discuss things become a member on the forum. Whoa. And if you want to see overclocking on GTX 1080 because it's like weird and there's like pull up per voltage point offset stuff. Click here because that's another video that's like a little advanced and interesting and video changes a bunch of stuff. I'm going to go have a nap.