Direct X 12 will allow multirender of GPU and IGP

Source: www.computerbase.de/2015-05/directx-12-mit-multiadapter-rendern-grafikkarte-und-igp-zusammen/


So apparently Direct X 12 will allow for your discrete videocard to work together with the integrated graphics.
Kind of an SLI / Crossfire of a discrete card with the onboard card.
According to tests in the unreal engine they got frame boosts from up to 11%
35,9 FPS vs 39,7 FPS.

So does means that Direct X 12 will bring us a performance boost, but its yet unknown which graphics cards this will support and if this will support SLI/Crossfire.


cheers

 

In theory, it shouldn't matter what cards. It's OS and game/application level, not driver or vendor dependent. So we could get patches for all kinds of games. It'd be slick if an iGPU, say, physics library started to get popular.

 

This is very interesting news, but I wonder how our laptops would cope with the combined heat from the CPU + iGPU + dGPU, especially those with a single cooler. Although perhaps the iGPU would barely produce any heat at all, compared to the others.

I have my doubts if we will actually see this implemented, but one can dream.

 

Asymmetric xfire

 

This is one of the main reasons for which I'll be upgrading to Windows 10. It sounds good, but we won't know for sure until we get to try it out.

Here's another interesting read: http://www.windowscentral.com/directx-12-windows-10-could-allow-gpus-nvidia-and-amd-work-one-pc

 

Is it gonna cure cancer too?

 

Hope this happens but doubt NVIDIA will allow it..

 

nVidia needs to find themselves on the wrong end of an antitrust lawsuit.

 

I would hate to deprive their CEO of his Ferrari allowance.

 

To remain DX12 compliant they have no choice, the software is splitting up the rendering. As for how good it is we will have to wait for real world numbers.

 

Well, it's not like they can't cripple this to "ensure the best user experience for their customers".

And how exactly does this work? Split frame? Alternate frame? Different passes on different hardware?


Edit: looks like different passes on different hardware, such as post processing on the weaker one.

 

AFR would be a nightmare

 

Afr would be the only way I think

 

No it isn't

 

Unless the scenes are intelligently rendered at a software level to support this

 

With such unbalanced throughput, AFR would be totally unusable.

The source seems to indicate post processing passes on the weaker GPU, assuming Google translate gets it right.

 

Which it has to be. Obviously it can't be done at driver level like AFR currently is.

 

Even AFR is not purely driver level without considerations on the application. What if the rendering code wants to access data generated from last frame?

 

Then Nvidia marks the game as not AFR friendly and doesn't release an SLI profile for it

 

DX12 in a nutshell:



Nice to know that some things in Redmond never change...

 

It won't be any hotter than it already is. CPU pushing peak or CPU + iGPU won't matter really since it's under the same TDP.

This has been done before, just it had limited support. AMD had been doing this for years with their asymmetrical crossfire, and there was some driver as well that would artificially boost 3Dmark scores but using a tech similar to this. It would be good to see it in reality, but if all you get is 11% boost, I don't see the point. I just see it as more issues and potential for increased frametimes and latency. SLI suffered and still suffers some issues to this day. This would have years of growing pains I believe before it would be of any real use.

 

An 11% boost isn't huge, but it is noticeable! Not too bad to gain 5 frames or so.

 

5 FPS gain for 50ms additional frame time variance :3

 

Ok true, I guess there is a downside

 

This reminds me of the hybrid SLI my M17xR1 had... It didn't work well at all and nVidia killed it.

 

Hybrid SLI?

 

Yeah. R1 had GeForce 9400M G onboard and 2x260M and it could use all three for SLI. It was not a smooth experience and nVidia killed support for hybrid SLI in their Verde drivers.

 

Yeah I remember that... It wasn't very popular lol due to driver problems etc

 

It just didn't make sense to combine such a weak GPU with two powerful GPUs. I didn't use it much because the 9400M was just too weak to bother. It only went unstable when pcie gen2 was enabled in the BIOS. The R1 was plagued with issues when it came out... Took Dell forever to fix them.

 

will there be much of an fps boost difference between say a typical intel hd 4000 vs an iris pro igpu? or because they are so low end, it won't matter?

 

this would probably mean higher CPU temps.

 

No, it would just mean more TDP throttle.

 

Iris Pro will smoke HD 4000. Iris Pro is about on par with a low end dedicated GPU, like a GT 640m/650m. Granted it will also consume more power and generate more heat and fan noise.

 

Yeah, not too interested in the "feature".. I don't have an unlocked BIOS for my AW so the 67W limit means every Watt I can squeeze out of my CPU will be used for CPU power and not iGPU..

 

Which one? Aren't there a couple that count as Iris pro?

 

Iris pro is just the top notch IGP with each respective iteration of CPU and includes eDRAM. 5200 is for Haswell, 6200 is for Broadwell, 7200 will probably be for Skylake, etc. There's also "Iris" graphics (non Pro) that don't include eDRAM, but same thing applies. 5100 for Haswell, 6100 for Broadwell, etc.

 

So basically - a bad version of the amd apu+crossfire setup. Brilliant.