Is Multi-GPU (for gaming) really dying? Or are people just saying that?

[antihelten]

Same idiots thought smart watches were the next big thing... look how they turned out. Also 3D TVs and games.... oh and motion controllers...

Whilst im sure its fun for a while i wonder how long you can keep that thing on your head without your eyes going funny and headaches coming.

The next fad.

Many tech sites did hype smartwatches, right up until the point where they got to review them, at that stage the response was much more tepid, VR on the other hand is getting incredibly strong reviews. 3D TV and games failed, not because the idea was bad, but because the tech was (and still is) bad (lack of compatibility/content, cumbersome setup, and too small of a sweet spot for 3D TVs), this is the same reason why VR failed in the past, but now looks set to succeed (the tech is finally good enough). Motion controllers will likely be making a big comeback in the coming years, due to VR.

Eye strain and headaches will likely be a problem in the early days, just like how it was a problem in the early days of TV and monitors. last I checked people are still using those.

 

[Silverforce11]

I would not go with multi-GPU these days. There are lots of major games without any multiGPU support. It's simply not worth the investment when it's AWOL in many games, and in the games that it has support, SLI scales very poorly, not the 80-90% like in the old days but down to 50-60%.

CF scales better when it works, but it works even less than SLI because lots of GameWorks titles has problems with CF, like The Division, Just Cause 3 etc.

 

[VulgarDisplay]

VR is not the next fad. It's the next logical step on the path that game developers have been following since the birth of the PC. VR is going to lead us to the holodeck from Star trek. That's the end goal. Another dream from Roddenberry will come to fruition. We've all got tricorders in our pockets already.

I expect the VR boom to drive GPU and display technology at a breakneck speed for the coming years. I'm not buying a vive or occulus this go around because I have no doubt that the next iteration is going to be much more complete product. I'll let the early adopters beta test for a few years.

Sent from my XT1575 using Tapatalk

 

[Silverforce11]

VR is not the next fad. It's the next logical step on the path that game developers have been following since the birth of the PC.

I've read about 6 or 7 reviews on the Rift when it was launched. Every single reviewer mentioned severe issues with nausea or feeling bad they had to remove the helm and take a break. This happened for some after 15mins, for others after 5mins.

ie. https://youtu.be/5RA0Ri1UW1A?t=5m38s

In games that limit their head movement, they could play it longer before feeling ill. But these games were on-rails, not really true 360 VR exp.

VR is a fad until they resolve this issue. Mainstream gamers will not folk out big $ for such a crap experience.

 

[maddie]

I've read about 6 or 7 reviews on the Rift when it was launched. Every single reviewer mentioned severe issues with nausea or feeling bad they had to remove the helm and take a break. This happened for some after 15mins, for others after 5mins.

ie. https://youtu.be/5RA0Ri1UW1A?t=5m38s

In games that limit their head movement, they could play it longer before feeling ill. But these games were on-rails, not really true 360 VR exp.

VR is a fad until they resolve this issue. Mainstream gamers will not folk out big $ for such a crap experience.

I'm not too sure it can be resolved. By this I mean that humans have always gotten motion sickness. Flying, driving, boating have always induced many to feel nauseous. The techs can work on any additional factors related to the VR equipment and software but in the end, we as humans suffer from nausea due to certain movements. In fact VR might be worse as you disconnect the inner ear from the visual stimuli.

Still believe its happening.

 

[VulgarDisplay]

I've read about 6 or 7 reviews on the Rift when it was launched. Every single reviewer mentioned severe issues with nausea or feeling bad they had to remove the helm and take a break. This happened for some after 15mins, for others after 5mins.

ie. https://youtu.be/5RA0Ri1UW1A?t=5m38s

In games that limit their head movement, they could play it longer before feeling ill. But these games were on-rails, not really true 360 VR exp.

VR is a fad until they resolve this issue. Mainstream gamers will not folk out big $ for such a crap experience.

Read reviews of roomspace games with motion controllers on the vive. Actually walking around and using your hands in a space fixes motion sickness.

The tracking on the vive is so good that you feel present in whatever scene you are in and your movements are 1:1 so you don't get disoriented.

There are videos where someone throws a motion controller to a person wearing the headset and they catch it just based on what they see in the vive.

Sent from my XT1575 using Tapatalk

 

[dogen1]

Also it's funny that you should mention a near doubling of FPS, as VR basically ensures that you will get that (plus perfect compatibility and zero microstutter)

From what I understand, that's not really true. Valve recently did a pretty nice presentation called advanced vr rendering, it's free online to watch if you're interested.

One of the major points they went over, in relation to performance, is that since shadows have to be rendered on both GPUs separately and because you have to transfer frame data more often, 2 GPUs only results in around a 35% performance improvement over 1. And 4 GPUs is only marginally(5-10% iirc) better than 2 because data transfer and synchronization becomes even more complex/costly.

The real advantage with multi GPU VR is the ability to render at much higher resolutions, not necessarily much higher performance. 2 GPUs should be able to handle ~2x the resolution as 1 and 4 GPUs 3-4x.

 

[Raising]

What ?

It's never been so alive, also how would I play games in DSR or 144hz ?

I can play Dark Souls III @ 4434 x 2494 @ 60fps with two 980tis for example, looks amazing ! Racing games are flawless too with DSR !

Every game I have works in SLI mode, and no I don't have any of these new garbage DX12 games that have released so far.

 

[UaVaj]

unless you are running 1) exotic resolution or 2) chasing high frame rate or 3) both.

a single 290x/390x/980 is sufficient at delivering enjoyable framerate/gameplay at 1920x1080 (which is the predominant desktop resolution per steam march 2016 survey).

given that said. there is really no need for multi-gpu especially with vega/pascal.

otoh
if reason #1 or #2 above applies to you. no choice but to multi-gpu.
and
especially if reason #3 above applies to you. even quad vega/pascal might not cut it.





btw. how many vega/pascal do you think is necessary for - 1600p x3 with all the eye candy and 60fps absolute minimum dip.

 

[alcoholbob]

Multi GPU support is getting more spotty. Most games were fullscreen DX11 in the past which means it was pretty easy to patch in SLI/CF. Now you are having PC gaming fracturing into all kinds of digital distribution platforms with their own quirks (like forced borderless windowed gaming or forced windowed mode, etc) and new APIs.

I feel going forward SLI/CF support is going to get much, much less consistent which means single GPU performance is going to become more important for a wide range of gaming.

 

[antihelten]

From what I understand, that's not really true. Valve recently did a pretty nice presentation called advanced vr rendering, it's free online to watch if you're interested.

One of the major points they went over, in relation to performance, is that since shadows have to be rendered on both GPUs separately and because you have to transfer frame data more often, 2 GPUs only results in around a 35% performance improvement over 1. And 4 GPUs is only marginally(5-10% iirc) better than 2 because data transfer and synchronization becomes even more complex/costly.

The real advantage with multi GPU VR is the ability to render at much higher resolutions, not necessarily much higher performance. 2 GPUs should be able to handle ~2x the resolution as 1 and 4 GPUs 3-4x.

I've already watched that presentation (and it's hardly recent, seeing as it's over a year old), and I have no idea where you get the 35% from, since the presentation specifically say that performance is nearly doubled.

Slide 13:

We have already tested the AMD implementation and it nearly doubles our framerate – have yet to test the NVIDIA implementation but will soon

Alternatively you might want to look at this more in depth presentation, one of the things pointed out here is that you do in fact not have to render shadows twice, so again I have no idea where you're getting your info from.

 

[bystander36]

I've already watched that presentation (and it's hardly recent, seeing as it's over a year old), and I have no idea where you get the 35% from, since the presentation specifically say that performance is nearly doubled.

Slide 13:


Alternatively you might want to look at this more in depth presentation, one of the things pointed out here is that you do in fact not have to render shadows twice, so again I have no idea where you're getting your info from.

There is a difference between presentations and reality. As someone who uses 3D Vision, I can tell you what my experience is.

If it was strictly about GPU grunt, my FPS will double with SLI. The problem is, the CPU side of things. In many games, the CPU power required nearly doubles and if the game pushes the CPU hard to reach 60 FPS in 2D, in 3D Vision, your FPS may only hit 30-40 FPS.

It varies from game to game. In some cases, but the issue is CPU bottlenecking, more so than SLI/CF scaling.

 

[Raising]

Multi GPU support is getting more spotty. Most games were fullscreen DX11 in the past which means it was pretty easy to patch in SLI/CF. Now you are having PC gaming fracturing into all kinds of digital distribution platforms with their own quirks (like forced borderless windowed gaming or forced windowed mode, etc) and new APIs.

I feel going forward SLI/CF support is going to get much, much less consistent which means single GPU performance is going to become more important for a wide range of gaming.

Uh.. SLI works in window mode and now recently DSR is also possible with SLI enabled, just because AMD is trash with their crossfire implementation doesn't mean multi gpu is "dead"

 

[Rakehellion]

I say a lot of things, most of which is marvelous BS, as you guys are fondly aware. But YOU guys have been saying something this time, and I am wondering if that too is marvelous BS.
MGPU is dead, or so its been said. I wonder if next round SLI makes sense, and my wallet should dread, or will a single GPU going forward put the issue to bed? Please advise in detail, if you would, here in this thread.

Dying? It was never more than a niche phoenomenon.

 

[antihelten]

There is a difference between presentations and reality. As someone who uses 3D Vision, I can tell you what my experience is.

If it was strictly about GPU grunt, my FPS will double with SLI. The problem is, the CPU side of things. In many games, the CPU power required nearly doubles and if the game pushes the CPU hard to reach 60 FPS in 2D, in 3D Vision, your FPS may only hit 30-40 FPS.

It varies from game to game. In some cases, but the issue is CPU bottlenecking, more so than SLI/CF scaling.

3D vision does not make use of the same stereo rendering techniques that AMD and Nvidia is implementing for VR, and as such your experience with 3D vision is irrelevant. 3D vision uses AFR, which is exactly the same as what is used for normal 2D displays and thus has many of the same issues we are used to seeing with normal crossfire/SLI setups.

In VR the CPU needs to push 180 frames per second (90 each for the left and right eye). In many games of today this would potentially be an issue, but the people at Oculus/Valve are not stupid, and tons of effort has been poured into reducing the CPU load (basically by reusing some amount of work done for one eye on the other eye).

Point in case the last presentation I linked has this quote:

Graphics API calls do not need to be doubled, which is what this slide stack covers.

 

[bystander36]

3D vision does not make use of the same stereo rendering techniques that AMD and Nvidia is implementing for VR, and as such your experience with 3D vision is irrelevant. 3D vision uses AFR, which is exactly the same as what is used for normal 2D displays and thus has many of the same issues we are used to seeing with normal crossfire/SLI setups.

In VR the CPU needs to push 180 frames per second (90 each for the left and right eye). In many games of today this would potentially be an issue, but the people at Oculus/Valve are not stupid, and tons of effort has been poured into reducing the CPU load (basically by reusing some amount of work done for one eye on the other eye).

Point in case the last presentation I linked has this quote:

In both, they render 2 frames for the same time frame. The only difference is that 3D Vision will send the frames at alternate times, but that is only due to monitor limitations. The way the scenes are rendered for the eyes still remain the same.

EDIT: interesting note about SLI and 3D Vision. 2-way SLI will split the use so 1 GPU renders the left eye, and the other renders the right eye. In 3-way SLI the 3rd GPU is not used, except for PhysX.

 

[Squeetard]

Multi GPU is dead to me. I have been running xfire or SLI in all my rigs since it came out. It's a pain in the ass. AMD and nVidia don't give 2 shits about supporting it. Just about every game that has come out has had some issue with it and months later, usually after you are done playing said game. They post a fix. Even games that 'work', have stuttering and frame pacing issues. A good example is the new Tomb raider.I have a smoother experience at 40 fps single gpu than I do at 75 fps in xfire.
Now that a single gpu is fast enough to play games (except 4k) on ultra I will finally rid myself of it.

 

[moonbogg]

Multi GPU is dead to me. I have been running xfire or SLI in all my rigs since it came out. It's a pain in the ass. AMD and nVidia don't give 2 shits about supporting it. Just about every game that has come out has had some issue with it and months later, usually after you are done playing said game. They post a fix. Even games that 'work', have stuttering and frame pacing issues. A good example is the new Tomb raider.I have a smoother experience at 40 fps single gpu than I do at 75 fps in xfire.
Now that a single gpu is fast enough to play games (except 4k) on ultra I will finally rid myself of it.

I could go that way easily and not be too bothered. I'm sure big Pascal will be quite fast and would be just fine by itself, but BF5 will ultimately dictate what I do. If it lags on a single GPU, then I will need two. OR maybe I can lower settings like a normal, reasonable person and save myself the money and headache. We'll see.

 

[Mopetar]

I don't think it's dying, but has merely hit a lull at that moment due to outside factors. We're seeing both companies releasing new products on a new node as well as a shift to DX12. Both of these are going to tie up resources to ensure that the new generation of product works well and has great performance, which means there aren't as many people to devote to doing multi-GPU support on the older products.

Several people here are of the opinion that going forward we'll likely see most cards use a multi-GPU approach by putting multiple small dies on an interposer as node shrinks make it increasingly difficult to properly yield for larger dies. Assuming that comes to pass, eventually everything will be some for of multi-GPU.

 

[sm625]

As soon as you can go on one of those camgirl sites and get VR cam girls, it will take off.

 

[poofyhairguy]

OR maybe I can lower settings like a normal, reasonable person and save myself the money and headache.

Nah.

 

[VirtualLarry]

I would not go with multi-GPU these days. There are lots of major games without any multiGPU support. It's simply not worth the investment when it's AWOL in many games, and in the games that it has support, SLI scales very poorly, not the 80-90% like in the old days but down to 50-60%.

CF scales better when it works, but it works even less than SLI because lots of GameWorks titles has problems with CF, like The Division, Just Cause 3 etc.

Not to mention, "Windows Store" games, with UWP, not supporting multi-GPU either, because of technical limitations.

 

[antihelten]

In both, they render 2 frames for the same time frame. The only difference is that 3D Vision will send the frames at alternate times, but that is only due to monitor limitations. The way the scenes are rendered for the eyes still remain the same.

EDIT: interesting note about SLI and 3D Vision. 2-way SLI will split the use so 1 GPU renders the left eye, and the other renders the right eye. In 3-way SLI the 3rd GPU is not used, except for PhysX.

I'm fairly certain 3D vision does not render 2 frames for the same time frame, nor should it for that matter, as that would lead to wonky looking animations. 2-way SLI with 3D vision does not specifically split rendering between eyes either, but since the order on which the 2 GPUs delivers frames is fixed when using AFR, they will end up doing so as a side-effect, not by design.

Using AFR you get poor scaling (since the load on the CPU is basically doubled), you get micro stutter (since AFR does not have any inherent way to smooth out delivery of frames), and you get so-so compatibility (much better than SFR at least).

With VR SLI/crossfire you get close to perfect scaling since the rendering of the 2 frames (left eye and right eye), is far more exposed and controlled (since the VR SDK is purpose built around rendering 2 frames at a time) and as such you can do a lot more optimization of the CPU side, which is exactly what has been done (this has also been done with a few 3D vision games such as Crysis 2, but they are few and far between). You also get zero micro-stutter, since VR effectively has built in smoothing, thanks to the fact that both frames are shown at the same time instead of one after the other like what happens with AFR. Finally compatibility should be very good, since all VR games has to make use of the SDKs (only possible exception being with Nvidias auto stereo feature).

So all in all multi-GPU on VR is a completely different beast from multi-GPU with 3D vision (or multi-GPU on a normal monitor for that matter).

 

[moonbogg]

Nah.

This is one letter longer than the shortest possible response in the English language, yet is still the most complete, comprehensive and truthful response in this entire thread. I applaud. I do applaud.

 

[digitaldurandal]

Uh.. SLI works in window mode and now recently DSR is also possible with SLI enabled, just because AMD is trash with their crossfire implementation doesn't mean multi gpu is "dead"

Having used both implementations, they both have their problems. SLI is not excluded from that. I've run into games on both that required me to disable multigpu due to severe frame judder or flashing textures etc.

I also nabbed 2x290s for under 500 bucks over a year ago now and quite often on newer titles I see it out performing it's 970 competition in both multi and single GPU.