MULTI-GPU/Crossfire/SLI?

[Mr. Damocles]

Will Multi-GPU and Crossfire support be coming?

[PrimeSonic]

I wouldn't begin to remotely get your hopes up.

Multi-GPU for gaming is going the way of the dodo.
Next time you upgrade, keep that in mind and spend twice as much on a single powerful GPU rather than two lesser ones.

[Cryten]

SLI/multi GPU is a bugger to program for and doesnt give much benefit when you run them as a simulated single core. Therefore only the biggest games ever programmed for it. As Alex said even the big games are stopping trying.

[Ancient]

Unity Engine games typically use deferred rendering for motion blur, bloom and and some other effects and that doesn't work with SLI. It's compatible, sure, but you get no scaling improvements if any of those effects, or any other deferred rendering techniques, are used within the game. They will just ignore the additional card(s) because SLI/CFX doesn't allow sharing of data between GPU's VRAM/framebuffers, so the 2nd (or 2nd/3rd/4th) GPU cannot render anything using those techniques that is based on data stored in the framebuffers of the 1st GPU.

More info on that here: https://support.unity3d.com/hc/en-us/articles/211505603-How-well-Unity-does-scale-with-SLI-

Another issue is that all Unity Engine games default to using a Borderless Fullscreen mode and not Exclusive Fullscreen, so SLI/CFX, Surround/Eyefinity, forcing AA modes via drivers, and downsampling using DSR/VSR aren't available without using the following command line argument to launch the game:

-window-mode exclusive

Needless to say, using that to use DSR/VSR, driver-based antialiasing, or to enable SLI/CFX or even Surround/Eyefinity are all technically unsupported in Unity. The option exists, but is not recommended or supported. Unless the specific game's devs went above and beyond to test out and make those things work, such as providing detection for and a proper UI layout that is compatible with 48:9 aspect ratio to support Surround/Eyefinity or ensuring that their game uses all non-deferred rendering techniques to allow for multi-GPU scaling to work properly, then it falls back on the default position which is that Unity doesn't support them.

[Mr. Damocles]

I dunno, they way it works on the games that support it, Arma-3 even Killing Floor-2, turns crap FPS into fluid smooth gameplay at max settings.

And the best part of Multi-GPU... NO RIBBONS connecting them,my motherboard handles all the translations, so you can stick 2 of the same card in, or mix and match Nvidia with ATI, and it will give better average FPS regardless of what Vidcards you install, and I still have an empty slot I could throw in a complete POS card and it would still improve average threading workload..

I'm running 3 Radeon RX-480x on my rig, and the games that I mentioned are so flawlessly smooth, it was worth it to buy them, 2 are MSI, and 1 is Gigabyte, and they work together in harmony.

When I run games that only use 1 card, performance drops bigtime.

[SlothGodJeff]

Don't mean to necro a post, but Mister.D has a really good point. 99% of the games I play, I run them with dual gpus even if they aren't supported because it helps split the workload and MOST of the time increases performance by a good margin.

The thing I think most people that complain about SLI/Crossfire is lack of support, but it's not that hard to emulate support or force it as long as you know what you're doing. I'd rather spend the extra 10 minutes it takes to get a game set up for Crossfire than have to go out and buy a new GPU for a few hundred dollars.