Multi gpu support?

[bgray9054]

@ CDPR / Moderation

Can you advise on what API the game is being made in and if it will have multi gpu support? Thanks very much.

[Mako Ruu]

It's way too early to predict this. But since the game is supporting Ray Tracing, it confirms that it will support Direct X 12.

However, it also needs to run on older hardware and consoles like PS4 and Xbox One. Which use older custom API's (PS4 uses OpenGL.)

[bgray9054]

Appreciate the response - ya, DX12 does have explicit mgpu support, would be nice if they code for it. Thanks again.

[Justin_760]

Probably not. Multi-GPU is dying, mostly intentional - NVIDEA and AMD dont want people saving money by buying two cheaper cards rather than one crazy priced new card. Its the very definition of bad business plan.

Very few games support the multi-gpu scaling necessary to actually use the second card. As far as I remember there have only been a few AAA games in the last couple years to actually do GPU scaling for this.

So Im going to predict that it wont. Its a relatively small crowd to cater to, as per steam hardware surveys very few people use multi-gpu's.

[8-fingered]

Originally posted by Justin_760:

Probably not. Multi-GPU is dying, mostly intentional - NVIDEA and AMD dont want people saving money by buying two cheaper cards rather than one crazy priced new card.

I think the biggest problem is the lack of support for it in Unreal Engine rather than any NVIDIA/AMD conspiracy to kill the technology. NVIDIA blogs about how to implement it:

https://developer.nvidia.com/explicit-multi-gpu-programming-directx-12

Even if there is a conspiracy, Microsoft isn't in on it:

https://www.pcworld.com/article/3039352/qa-microsoft-platform-gaming-chief-mike-ybarra-on-the-future-of-directx-mobile-gaming.html

Originally posted by Justin_760:

So Im going to predict that it wont. Its a relatively small crowd to cater to, as per steam hardware surveys very few people use multi-gpu's.

I don't see anything about multi-gpu setups in the steam hardware survey results.

[FeilDOW]

https://youtu.be/7_1OWdNDNLg

[bgray9054]

At this point I think a lack of multi gpu support would probably be the only thing that would make me hold off on purchasing. I trust CDPR in all other areas to deliver (no MTX, no exclusives for other platforms, etc.) a quality product given their positive track record.

[8-fingered]

Originally posted by FeilDOW:

https://youtu.be/7_1OWdNDNLg

SLI worked great in Witcher 3 with REDengine3. So the question is, did CD Projekt RED disable perfectly functional DX11 SLI support in their engine when they put in all the NVIDIA DX12 tchotkes like 4A Games did with Metro Exodus? If so will we be able to hack the executable to get it back like with Metro Exodus? DX12 mGPU would also be welcome, but I'm not holding my breath since they seem to have drunk the ray tracing Kool-Aid.

[8-fingered]

Originally posted by bgray9054:

At this point I think a lack of multi gpu support would probably be the only thing that would make me hold off on purchasing. I trust CDPR in all other areas to deliver (no MTX, no exclusives for other platforms, etc.) a quality product given their positive track record.

Prepare to be disappointed. I hope I'm wrong, but once they announced the ray tracing, I figured mGPU was done, just like with Metro Exodus.

[bgray9054]

Originally posted by 8-fingered:

Originally posted by bgray9054:

At this point I think a lack of multi gpu support would probably be the only thing that would make me hold off on purchasing. I trust CDPR in all other areas to deliver (no MTX, no exclusives for other platforms, etc.) a quality product given their positive track record.

Prepare to be disappointed. I hope I'm wrong, but once they announced the ray tracing, I figured mGPU was done, just like with Metro Exodus.

Oh when it comes to developers, NVidia, and the like, being disappointed is pretty much par for the course these days. I am holding out a smidge of hope because it's CDPR though. :)

[8-fingered]

Originally posted by bgray9054:

Oh when it comes to developers, NVidia, and the like, being disappointed is pretty much par for the course these days. I am holding out a smidge of hope because it's CDPR though. :)

I once had faith in 4A. No more.

[Jamison]

Yeah, as others have stated, probably not. At best GPU scaling was a niche project back in '05-'07. It's getting extremely rare to see games supporting it. To be honest, I'm surprised nVidia even bothered to come out with nvlink.

bgray9054, you will more likely have better luck asking on the official forums[forums.cdprojektred.com]

[FeilDOW]

Originally posted by 8-fingered:

Originally posted by FeilDOW:

https://youtu.be/7_1OWdNDNLg

SLI worked great in Witcher 3 with REDengine3. So the question is, did CD Projekt RED disable perfectly functional DX11 SLI support in their engine when they put in all the NVIDIA DX12 tchotkes like 4A Games did with Metro Exodus? If so will we be able to hack the executable to get it back like with Metro Exodus? DX12 mGPU would also be welcome, but I'm not holding my breath since they seem to have drunk the ray tracing Kool-Aid.

That was 4 years ago when SLI was actually supported in a decent amount of games.

I found with my SLI 1080 ti's if you needed to use workarounds for it it never ran smooth or had other issues like consistent crashing or flickering. IMO it's better to buy the fastest single GPU you can the only reason to SLI these days is if you have a 4k 144hz panel and need two of the fastest GPU's available.

[bgray9054]

Originally posted by Jamison:

bgray9054, you will more likely have better luck asking on the official forums[forums.cdprojektred.com]

Ya I've posted on CDPR's forums as well and can't get an answer at all. If the answer is no, that's fine, I'd just like to know. I would then just hold off on buying the game for a while, no biggie. Still love CDPR as a developer.

[8-fingered]

Originally posted by FeilDOW:

That was 4 years ago when SLI was actually supported in a decent amount of games.

It's not like code rusts. Unless they ripped it out, it's still in there.

Originally posted by FeilDOW:

I found with my SLI 1080 ti's if you needed to use workarounds for it it never ran smooth or had other issues like consistent crashing or flickering.

I've got a buddy with the same hardware with the opposite experience.

Originally posted by FeilDOW:

IMO it's better to buy the fastest single GPU you can the only reason to SLI these days is if you have a 4k 144hz panel and need two of the fastest GPU's available.

We're nearing the end of the road for Monolithic GPUs:

https://pcper.com/2017/07/nvidia-discusses-multi-die-gpus/

If you think NVIDIA and AMD are going to make some kind of fancy layer that makes those look like a monolithic GPU to ease the burden on developers after the way they dumped the work on them with DX12....well....

[Kaldaien]

Originally posted by Justin_760:

Probably not. Multi-GPU is dying, mostly intentional - NVIDEA and AMD dont want people saving money by buying two cheaper cards rather than one crazy priced new card. Its the very definition of bad business plan.

The actual problem is that the two cheaper GPUs are only as powerful as the weakest link in the chain. In the case of std multi-GPU, they're identical and you have a high-latency very high variability Frankenstein's monster built from 2 GPUs inadequately equipped to solve the problem at hand.

High frame rates are not the reason you buy more expensive GPUs these days, it is frame rate consistency at high resolution, which cannot be solved by throwing two cards that are already struggling to stay afloat at the problem. Multi-GPU simply has no relevance in any modern render workload -- too high latency for VR, too variable for high resolution.

On paper your thinking seems rational. However, I've actually developed for Multi-GPU in the past in SFR, AFR, mixed-SFR-AFR (requires 3- or 4-way SLI). The only reason Joe Average consumer believes Multi-GPU to be practical is because the only performance data they have to go by is benchmarks that measure average framerate.

Qualatatively, the experience with SLI is actually worse once you introduce metrics relevant to the problem being solved (avg. framerate is almost never relevant when discussing a render problem you wish to solve by throwing more hardware at).