DX12: Say Goodbye to Red vs Green?

[kelvindeschutter]

the sli scaling is surprisingly near perfect

[That Norwegian Guy]

32 minutes ago, Suika said:

Uhh... I think you have the wrong chips. The 960 is GM206 and 970 a cut down GM204. Do you mean 980 + 970?

 

36 minutes ago, KeltonDSMer said:

Not to be a downer, but 960 is full-fat GM206 and 970 is cut-down GM204.

Whoops, I mixed up: the GTX 760 and 770 were what was going through my head as I posted, not the 960 and 970.

[No Nrg]

Techpowerup.com did a write-up on this explaining how it works:

http://www.techpowerup.com/reviews/Performance_Analysis/Ashes_of_the_Singularity_Mixed_GPU/2.html

 

Quote

 

New DirectX 12 Multi-GPU Features

One of the highlights of DirectX 12 is its explicit multi-adapter support, which lets you harvest various GPUs for accelerated rendering performance. Unlike SLI or CrossFire, it is vendor agnostic and can combine the performance of any GPU with that of another instead of having to work with GPUs of the same architecture or a set of similar performance characteristics. All you need is DirectX 12 API support.



In DirectX 12, each video card has its own unique memory storage, which is unlike SLI or CrossFire where everything is mirrored. Gone are the days where the total video memory your 3D app could see is that of a single card. Two 4 GB cards make 8 GB of usable video memory and not two copies of 4 GB, for example. Microsoft innovated a new method of rendering with multiple GPUs called "Split Frame Rendering" (SFR). This breaks the 3D scene into tiles each GPU renders. The best part? Resources need not be perfectly mirrored between the two GPU systems, and as such, they have independent memory pools which add up to the machine's total available video memory.



Another key DirectX 12 feature is asynchronous shaders (async shaders). This feature allows a GPU's SIMD number-crunching resources to be optimally utilized.

 

 

From what I've read the overall performance boost you get with mixed GPUs is limited to the your slowest card. The best scaling results were mixing two cards with similar performance.

http://www.techpowerup.com/reviews/Performance_Analysis/Ashes_of_the_Singularity_Mixed_GPU/4.html

Quote

Let's now look at mixing different GPUs. The first takeaway here is that the slowest card will play a huge role in determining the final performance result. A GTX 980 Ti paired with a R9 380, for example, doesn't even get close to GTX 970 single-GPU performance. When looking at the original R9 380 numbers, though, we see a 78% performance uplift. In conclusion, you'll ideally want to pair cards of similar performance with each other to maximize your setup's price-to-performance ratio.

 

 

Another interesting effect becomes apparent when looking at identical combinations, just by swapping the first and second GPU around. The first GPU is always the one the monitor is connected to. Here, we see that using the faster GPU, which is the Fury X, as the primary card results in better overall performance. Looking at the Fury X+GTX 980 Ti, just swapping your monitor#s cable around can provide a 5% performance uplift.

 

 

 

 

 

[VagabondWraith]

If this doesn't benefit nVidia in a meaningful way, it'll never happen. It's nice to dream, but like the Fury X "overclockers dream," some dreams just have to die.

[BroliviaWilde]

55 minutes ago, dragosudeki said:

Doubt anyone is going to buy cards from both vendors (or completely different cards from same vendor) knowing that the number of DX 12 games (right now) is small, and the number of DX 12 games that use Explicit Multi GPU will be much more smaller than that.

I think the people who would be running mixed cards are those that have one now(such as a 280x) and are on the verge of upgrading beause maybe they want VRR and are ready to take the plunge for a new card and a new monitor.  Now that older card has potential to still be put to good use.

[patrickjp93]

33 minutes ago, Zodiark1593 said:

Perhaps if we're fortunate (like a 2% chance) bith gpu companies will kiss and make up, and keep down the insurgence of Intel iGPUs.

 

Could happen...

Wouldn't it be better to have the multiadaptor games just use all graphics resources available, iGPU included? Further, wouldn't competition from Intel in this arena be good for lowering dGPU prices?

[Kherm]

I love how 980 + 980 SLI scales worse than 980 + 980 Multi-GPU 

[Omon_Ra]

24 minutes ago, No Nrg said:

Techpowerup.com did a write-up on this explaining how it works:

http://www.techpowerup.com/reviews/Performance_Analysis/Ashes_of_the_Singularity_Mixed_GPU/2.html

Thank you! I wanted a more technical article to read.

[Zodiark1593]

29 minutes ago, patrickjp93 said:

Wouldn't it be better to have the multiadaptor games just use all graphics resources available, iGPU included? Further, wouldn't competition from Intel in this arena be good for lowering dGPU prices?

Know what, I agree. In an ideal world, neither silicon nor clock cycle on your system would go to waste.

[NateGSR117]

Nice and all but who really going to go through the effort no the market with sli enable system are small. But this is pretty awesome either way.

[MEC-777]

Very cool!  This is the kind of stuff we need to happen to push and advance this tech further. No more "continuing with what has been for many years". 

 

Just keep in mind; this still will not make cards like the 980ti obsolete because this will only work in the games that support it. For all other games that are still DX11 or don't implement this feature, you'll still need a single high-end card.

[cesrai]

The scaling beats SLI

[GoodBytes]

Ars has a nice article that they just released with more benchmarks, and more information on the different DX12 modes, which may explain why some games wont get performance advantages, and setups that drops performance.

http://arstechnica.com/gaming/2016/02/directx-12-amd-and-nvidia-gpus-finally-work-together-but-amd-still-has-the-lead/

 

For example they say:

Quote

Not all testing of EMA was positive, though, with

Guru3D reporting

huge amounts of micro-stuttering and frame pacing issues using its FCAT system. It also found that AMD cards were stuck with v-sync on at the display end—the Ashes benchmark takes its FPS numbers from the rendering port before the image hits the display—thanks to AMD's drivers not supporting the DX12 feature DirectFlip, which affected its testing.

So it really depends on the game and configuration. Some might work better than others. Can't wait for the forum to be filled with thread with every single game of people complaining about issues, not understanding that it may be game based, and hardware configuration.

[Ex14]

hmmm... wouldnt the real benefit for this come from using the igpu now in intels chip with our dgpu? i mean most of us have i5s and i7s. its like free performance rofl why not

[Doobeedoo]

Good thing for sure, if supported well.

Mainly excited about VRAM pooling and new frame rendering. It seems such a step forward as far as how to utilize new GPUs so can't wait to see it in action in games.

[Mo_z_Art]

Great!

Now people who can't decide between the two (like me) don't have to anymore (if they have the money...[not like me ])!

[samcool55]

More evidence here:

http://be.hardware.info/reviews/6576/6/ashes-of-the-singularity-review-directx-12-getest-multi-gpu-r9-fury-x-enngtx-980-tin (dutch, but should be easy to read the imporant things and to navigate)

Fury X and 980 ti, working just fine.

Also, the 960 completely shits itself on DX12 and performs worse, no idea why. Could have to do with the fact AotS needs more than 2GB Vram but that's not confirmed.

[Master Disaster]

Nvidia will kill this off before it ever goes public.

 

Its a great idea in theory but there's no way Nvidia will allow dual Nvidia+AMD setups, there's more chance of that predicted snow in hell than that ever happening, which is a shame.

[dragosudeki]

6 hours ago, BroliviaWilde said:

I think the people who would be running mixed cards are those that have one now(such as a 280x) and are on the verge of upgrading beause maybe they want VRR and are ready to take the plunge for a new card and a new monitor.  Now that older card has potential to still be put to good use.

I can somewhat agree, but what I said still applies. I don't know why someone would keep their old GPU in for a DX12 specific feature that requires developer support/implementation. DX12 is still not widely used and may not be for awhile. Then you're also counting on developer support to properly implement this feature. Currently, people are afraid of poorly optimized game releases, so how can people not be worried that this feature may not even get implemented.

[Belgarathian]

This has always been part of DX12 from day one. It's just that there is only one developer who has implemented this tech so far... Oxide Games. Not to crush anyones hopes or dreams, but most people don't even implement SLI or Xfire very well, so I'm going on record to say that implementation of explicit multi-adapter is going to be pretty much nill. 

[vanished]

15 minutes ago, Belgarathian said:

This has always been part of DX12 from day one. It's just that there is only one developer who has implemented this tech so far... Oxide Games. Not to crush anyones hopes or dreams, but most people don't even implement SLI or Xfire very well, so I'm going on record to say that implementation of explicit multi-adapter is going to be pretty much nill. 

That's why I worry about the whole concept of DX12 and Vulkan as well to be honest.  The idea is to give developers more low level control - more power if you will - so they can do exactly what they want an squeeze more performance out of the cards.  But if history can tell us anything, it's that most developers have a terrible track record of failing to implement or poorly implementing things like SLI/crossfire, or even general game optimization, so I'm not sure how anyone expects them to handle this and make things better.  It's like going up to a baby that can't walk and saying "OK, no rules - now you can run a marathon right?"

[JWMutant]

I think its a good move all round.

 

Lets face it Green do some things better and Red do other things better that green doesnt.

 

But more interesting is how this will effect gaming in general. Its no big secret that some games released are optimized to run better on some cards over another.

[beebskadoo]

This is cool but not practical when it comes to GPUs from different manufacturers i.e. Nvidia+AMD working together. The sheer amount of frame pacing issues make this completely useless in my opinion. To solve this both companies would have to release drivers that are meant to optimize the workload between each of the different cards and I personally don't see that happening anytime soon. 

[BuckGup]

I mean cool but really if say a 980 is better then a whatever on the AMD side wouldn't you just get 2 980s? The technology is cool and probably has some great benefits but I would get 2 980tis rather then a 980ti and a fury x

[Big-G]

This is great.. the birth of Team Brown fanboys