Published: Oct 19, 2019
Is SLI really dead and buried like some claim, or is such a notion some straight-up digital dogma mindlessly parroted in machine-like fashion by the envious or uninformed in forums and tech communities? Or perhaps the idea of SLI being dead is but a half-truth, with the answer depending solely on the context. Let's discuss both sides of the argument, and look at the state of SLI and multi GPU gaming in 2019, including a comparison of all the known pros and cons.
The multi-GPU debate has been prevalent in enthusiast circles for years now, and continues on through 2019 with the latest generation of RTX Turing graphics cards from NVidia which has actually brought renewed hopes for the future of dual video card gaming PCs with a new and improved version of SLI called NVLink which brings some bandwidth benefits to multi-GPU setups. The technology has been around in workstation machines for a while now, but this is the first time NVLink has been introduced into the consumer gaming space.
But just like discussions on most nuanced and somewhat complex topics, the wonderful world of cyberspace is a double-edged sword of a source if you seek accurate insight and knowledge on the heated SLI debate, and is expectedly filled with incomplete, misleading or straight-up inaccurate thoughts and takes on the state of SLI. It is a subjective thing too though, and everyone is free to their own opinion, but there is a lot of in-factual information and baseless claims, especially from those who strongly claim that SLI is 100% dead and buried for every single use case.
The fact is, nobody knows the future of SLI/multi GPUs with complete and utter certainty (I'd guess NVidia probably doesn't even know), and despite waning support for the technology over recent years on both a hardware and software level, in 2019, SLI is most definitely still a thing (albeit very, very niche; more on that in a sec). If you're currently weighing up the pros and cons of building a SLI gaming PC (see that guide for the basics) and are only getting more confused as you deepen your research into this mysterious matter, I'll try to shed some light as objectively and clearly as possible by clearly stating all known pros and cons to using SLI for gaming below.
I'll add my own thoughts too, based on not taking any one side and having carefully monitoring the state of multi GPU gaming for a while. Though I must admit I would love to see a SLI resurgence, because in future I do plan on setting up some monster-resolution gaming setups as it's always been a dream of mine since I was a kid, and no single gaming GPU setup is going to handle 8K or even 4K 144Hz gaming flawlessly on maxed settings without a partner card in crime (though to be fair 4K 144Hz cards may not be far away).
When you see discussions surrounding whether or not SLI is "dead", or more specifically whether it's worth building a PC for SLI in 2019 or not, it's easy to get confused as you'll see fair arguments for both sides of the coin. There's many ways you could look at the SLI situation and whether or not its day is done and dusted.
When you hear people say SLI is dead or is dying, what they really mean to say is that it's not worth the trouble. Which is in fact true - for most people. Some people talk about SLI as if it's meant for the mainstream, when it really isn't. For a certain small percentage of enthusiasts and high-end gamers, it can still be a rewarding path assuming you understand what you're getting into.
But first, let's clarify something straight-up; SLI is indeed dead for gamers who seeks value for money. In the past, SLI was more mainstream, and more mid-range GPUs supported it (along with more games) and a common strategy to be cleverly cost-effective would be to combine mid-range GPUs in the hopes of getting slightly better performance than a single more expensive graphics card.
See Also: Common SLI/Multi-GPU Myths Explained
While technically still possible to do, and it might work in some games, mid-range (or mainstream) SLI is a thing of the past. Years ago, more mid-range GPUs would come with SLI compatibility, such as the GTX 960 from the 900 series back in the day, but nowadays it's mostly only high-end GPUs that come with SLI support (although to be fair the latest RTX 2070 Super does have SLI support and you could consider that mid-range).
But what makes mid-range SLI dead and a bad idea, besides the fact that only higher-end cards support SLI in modern times, is the fact that the drawbacks of a SLI system are not worth potentially getting slightly higher frames over a single more expensive card.
For example, even in SLI supported games that scale well, depending on your hardware, software, settings, etc - it's entirely possible to encounter what's known as micro-stuttering, which is basically visual artefacts/glitches which can hinder the smoothness of your gaming experience and make SLI not worth it for that particular game despite the higher frame rates (though it's possible to get rid of the stuttering by doing some research and tinkering with your settings).
Plus, when you factor in the SLI bridge and the added power and cooling requirements, you're not going to save much if any money. In days gone by you could also do 3-Way and 4-Way SLI, but with the release of the GTX 10 series 3 and 4-Way SLI is most certainly dead for gaming at least (workstation Quadro GPUs for 3D rendering applications are another matter).
While it was a murkier decision in the past due to various factors such as better game support, more mid-range GPUs that supported SLI, and so on - in modern times if you're thinking of 2 slower GPUs vs 1 single more powerful one, you should always just get the single better GPU. But what's definitely NOT dead is SLI for hardcore gamers with deep pockets and no concern for maximizing bang for buck. In other words, those who crave more performance than what is possible with a single top-tier card like a RTX Titan or RTX 2080 Ti, and who're willing to pay a premium for it and also willing to accept that their second GPU won't be usable in every game.
Nobody knows the future of SLI besides perhaps NVidia (though I'd guess they don't even know), and the future of multi GPU technology is as murky as it's ever been. But for the time being, 2-Way SLI is still an option for a state of the art gaming PC in 2019, as the latest RTX 20 series range of GPUs like the RTX 2080/Super and RTX 2080 Ti do still support SLI using the new NVLink bridge connections.
The fact remains, SLI can still work well in certain games as has been (and continues to be) proven by multiple benchmarks you can easily find online, so it's far from dead. If you're on the cutting edge and gaming on maxed settings on a 4K 144Hz or 8K monitor (or want 60FPS with RTX real-time ray-tracing enabled), the only way to get flawless performance with those crazy demands of pixels/frames is with two cards (in AAA demanding games, that is).
Is SLI dead in 2019?
For the mainstream and 99.9% of gamers? Yes.
For the 0.1% on the cutting edge of pixel counts with money to burn? No.
Is SLI being phased out by NVidia? For mid-range GPUs, yes. For high-end GPUs? Nobody knows.
Has SLI support declined in official AAA games? In recent years, yes.
How many games will support SLI in the future? Who knows.
Is there a possible resurgence in SLI on the horizon thanks to its faster successor NVLink (and DX12 mGPU)? Yep.
So, even if SLI is alive for a minor segment of the enthusiast gaming population, is SLI actually worth it though? As the saying goes, just because you can do something, doesn't mean you should. There's obviously no black and white answer, and it'll depend on your patience and willingness/interest in tweaking settings manually, your levels of expectations, the games you play, your monitor, and so on.
SLI can be worth it to one extreme gamer, and a waste of time and effort for another. Notice I didn't say waste of money, as by now you should understand that SLI likely won't give you a direct return on investment; when you add a second RTX 2080 Ti to a system, you're paying a premium for only slightly extra performance in most games that support SLI (most won't scale performance by too much FPS, excluding a few lucky outlier titles).
SLI doesn't scale linearly, so in other words you're not going to get double the performance by adding a second card. How much faster SLI is compared to a single GPU varies from game to game and could be pretty much anywhere in the vicinity of a lousy 10-15% to around 70-90% in the very best case scenario. In some games you'd even seen worse performance with SLI mode enabled, even in games with official support, in which case you'd want to disable SLI for that game.
But if you fully understand what you're getting into and have the money for high-resolution 4K 60Hz/144Hz, 5K, or 8K gaming I'd say go for it if your favorite titles are supported (or have fixes posted online with multiple reports of people using it successfully). Personally, I plan to build a dual water-cooled RTX 2080 Ti system in 2020 (for my upcoming water cooling PC build), and you can bet your bottom dollar I'll be posting full details here on BGC (with photos and/or videos).
Anyway, let's wrap with a simplified side by side look at all the main pros and cons to SLI:
Potential Benefits of Having a SLI PC:
Potential Downsides of Having a SLI PC: