DirectX 12: The future of it within the console gaming space (specifically the XB1)

[sebbbi]

These "features" are in a multitude of long sold hardware of different vendors.

VLIW Radeons didn't support bindless resources, while GCN, Fermi and Kepler do. Same is true for sparse textures (GL_AMD_sparse_texture). Only GCN support it. Fermi and Kepler support OpenGL 4.4 equivalent (GL_ARB_sparse_texture).

 

[pjbliverpool]

http://arstechnica.com/gaming/2014/...ovements-for-existing-hardware-in-directx-12/


Other than the Xbox One and the JPEG move engine, do any other current DX11 GPU which now claim to be DX12 compatible actually have hidden hardware for ASTC and JPEG acceleration which just hasn't been exposed up to now? If not, is ASTC and JPEG acceleration going to be emulated either on GPU with shaders or by the CPU for older GPUs or will it simply be an optional part of the DX12 spec?

That's quite interesting, I wonder if the "additional DX12 hardware features" that PC GPU's will need are what the XB1 already provides via it's move engines/display planes etc...

 

[Pixel]

That's quite interesting, I wonder if the "additional DX12 hardware features" that PC GPU's will need are what the XB1 already provides via it's move engines/display planes etc...

In the Digital Foundry article they explained the benefit of the move engines alleviating the cpu in the movement of data. But given desktop PC cpu's generally are more powerful than what is in the consoles even with half the cores, and ontop of that there are inefficiencies in further and further parallelizing across console 8 cores, I don't see why AMD would would bother dedicating silicon space to it, especially with these new APIs/API (even opengl) updates reducing api overhead, and given PC hardware will continue to improve by late 2015.

Now if this is largely targeted at the mobile sector with its apus, that makes sense as desktop sales are dwindling and mobile is where the cash is at for these companies. This would also improve cpu performance which is important for playing games and where cpu can be a bottleneck. Directx is now not just for high end PCs, they want to compete with Opengl ES in the mobile sector, so they need to align with AMD's interests in that sector if they want success.

 

[MetalSpirit]

This is great news, so we basically get the best of both worlds - graphics hardware continues to progress at the feature level while even older GPU's get the full benefit of the more efficient API.

This does raise some interesting questions though...

1. Will these features merely be the DX11.2 features already included in GCN 2.0?
2. If they go beyond that then presumably XB1 will only be 'partially' DX12 complaint.
3. Will Maxwell support the new features or will we have to wait for Volta?

Lets just not forget that Kepler does not implement the Full Dx 11.1 (lacks four non-gaming features for hardware feature level 11_0) or Dx 11.2 (no tier 2) specs. So for Nvidia to be able to claim full DX 12 support, it would require new hardware anyway.

 

[MetalSpirit]

I didn't on purpose; the nvidia blog mentioned their involvement on dx12 for 4 years with ms and a implementation period of over a year now today. I just stayed on that thought. Realities are likely that this group joined together to discuss these items either directly together or indirectly. But I could imagine 4 1on1 discussions being different than 4 groups actively working together.

I find it curious that Nvidia claims DX 12 was in development for four years. Yet the AMD Vice President gives an interview last year saying that "as far as the company can see, there will be no DX 12". And even more, AMD invests heavily on a new API for low level acceleration even though DX 12 is on the works.

Whats going on here?

 

[Kaotik]

I find it curious that Nvidia claims DX 12 was in development for four years. Yet the AMD Vice President gives an interview last year saying that "as far as the company can see, there will be no DX 12". And even more, AMD invests heavily on a new API for low level acceleration even though DX 12 is on the works.

Whats going on here?

Nothing special, I think.
He's a marketing guy, talking about near future, where DX12 doesn't exist - at that point something coming out in 3 years is irrelevant.
Also, considering that DX12 has been in actual development for about a year, it's not farfetched to assume he could be talking about the fact that DX12 wasn't in development yet, even if there was talks about it.

 

[3dilettante]

Microsoft said discussions about future improvements to DX or reducing overhead were started four years ago, Nvidia's stated time frame for its (edit: Nvidia's) active development was shorter--roughly a year, I think.

 

[Ethatron]

VLIW Radeons didn't support bindless resources, while GCN, Fermi and Kepler do. Same is true for sparse textures (GL_AMD_sparse_texture). Only GCN support it. Fermi and Kepler support OpenGL 4.4 equivalent (GL_ARB_sparse_texture).

GCN is "long sold hardware" in my time table.
Hardware support != software support. Bindless and descriptor is around in HW way longer than the OpenGL extension.

 

[Kaotik]

Microsoft said discussions about future improvements to DX or reducing overhead were started four years ago, Nvidia's stated time frame for its (edit: Nvidia's) active development was shorter--roughly a year, I think.

Where exactly did you pick this from? I've only seen NVIDIA referring to anything happening 4 years ago

 

[3dilettante]

I found that both Microsoft and Nvidia stated discussions began four years ago. I'm trying to find the article or slide for Microsoft.

Per the following:
http://blogs.nvidia.com/blog/2014/03/20/directx-12/

The collaboration to create a working design was over the past year.
It's not a hard timeline, but it seems reasonable to interpret both Microsoft's statements and Nvidia's disclosures as indicating the early phases of the last four years were taken up with discussion and planning.
Creating a working design hasn't involved Nvidia until roughly 2013.

It's possible Mantle kicked off as an independent initiative to force some end to the talking phase that started four years ago.

 

[Dave Baumann]

He's a marketing guy...

Sales.

 

[Pixel]

Any info about Opengl's timeline?

 

[madyasiwi]

It's 3 because nvidia support bindless resources(not textures) and drawindirect since Fermi - http://developer.download.nvidia.com/opengl/tutorials/bindless_graphics.pdf , but I suppose Fermi will have limited support(some feature level like DX11's feature level 10 for compute shaders on DX10 cards)

NV's G80/90 and GT200 GPUs support some form of bindless capability too.

GlCapsViewer

Edit:

http://www.hardware.fr/news/13625/gdc-direct3d-12-support-materiel-logiciel.html

In hardware Direct3D 12 support, Microsoft stated that it was possible at the level 9_3 functionality. By cons, to support Direct3D 12, in addition to supporting graphics features related to minimum hardware level, the architecture of the GPU will be able to some things. The main point is the inclusion of an MMU (Memory Management Unit) to virtualize and protect video / memory system, which makes sense considering how works Direct3D 12. This is why AMD and Nvidia can not offer support for Direct3D 12 that dates as far back as their GPU 9_3 class. By cons in the mobile world there are relatively recent 9_3 GPU which include an MMU and can therefore support Direct3D 12. Recall that AMD announced support for the new API for all GCN GPU, Nvidia GPU since all the Fermi generation Intel Haswell CPUs. In the case of Qualcomm, recent GPU are capable of support and will be offered on a case by case according to the demands of its customers. Finally, Xbox One bear Direct3D 12.

 

[MetalSpirit]

Nothing special, I think.
He's a marketing guy, talking about near future, where DX12 doesn't exist - at that point something coming out in 3 years is irrelevant.
Also, considering that DX12 has been in actual development for about a year, it's not farfetched to assume he could be talking about the fact that DX12 wasn't in development yet, even if there was talks about it.

I have a hard time getting that. If ATI just shutted up the result would be the same without any lies.
This was one of the motives I believed DX 12 would not require new hardware. Xbox was on development under ATI and yet they claimed this.

Now Nvidia comes to say that new hardware will eventually be required. Are they talking future DX 12.1? (DX 12 will NOT require new hardware and DX 11 cards will support it, and this was claimed by Microsoft itself on its DirectX development blog).

 

[Kaotik]

I have a hard time getting that. If ATI just shutted up the result would be the same without any lies.
This was one of the motives I believed DX 12 would not require new hardware. Xbox was on development under ATI and yet they claimed this.

Now Nvidia comes to say that new hardware will eventually be required. Are they talking future DX 12.1? (DX 12 will NOT require new hardware and DX 11 cards will support it, and this was claimed by Microsoft itself on its DirectX development blog).

DX12 API will work on DX11 (or some of DX11) hardware, but not all DX12 features will. The question is whether XB1 can do all the features too, and if so, GCN 1.1 and possibly 1.1 should be able to, too

 

[pjbliverpool]

DX12 API will work on DX11 (or some of DX11) hardware, but not all DX12 features will. The question is whether XB1 can do all the features too, and if so, GCN 1.1 and possibly 1.1 should be able to, too

Unless those features are part of the XB1's custom units like the move engines, e.g. jpeg decompression.

 

[iroboto]

Related - but slightly off topic from Xbox One

Nvidia Making Improvements to DX11 performance
http://www.pcper.com/reviews/Graphics-Cards/NVIDIA-Talks-DX12-DX11-Efficiency-Improvements

And Nvidia's GTC 2014 Keynote @ 0900 PDT
Perhaps more discussion on above DX11 improvements as well as DX12?
http://www.twitch.tv/nvidia

Some notes from the blog; as per some discussion in this thread

NVIDIA is currently the only GPU vendor to have a DX12 capable driver in the hands of developers and the demo that Microsoft showed at GDC was running on a GeForce GTX TITAN BLACK card. (UPDATE: I was told that actually Intel has a DX12 capable driver available as well leaving AMD as the only major vendor without.)

 

[MetalSpirit]

DX12 API will work on DX11 (or some of DX11) hardware, but not all DX12 features will. The question is whether XB1 can do all the features too, and if so, GCN 1.1 and possibly 1.1 should be able to, too

DX 11.2 will work on DX 11.1 hardware too. The diference is that not all features are available! But can I say a card without those features supports DX 11.2??

Kepler for instance, it has no Tier2 support. Can I claim this card supports DX 11.2? I think not!

Question is: To use DX 11 you need DX 11 hardware support, and to use DX 11.2 you need DX 11.2 hardware support. Yet Microsoft claims 80% of all currently sold cards will support DX 12.

I do not doubt new features in DX 12 will eventualy require specific hardware that not all (or even any) current cards support. But with current claims I doubt that will happen on the first DX 12 release. Maybe on future revisions (that may appear at almost the same time as DX 12).

From the DirectX developers blog:

Q: Should I wait to buy a new PC or GPU?
A: No – if you buy a PC with supported graphics hardware (over 80% of gamer PCs currently being sold), you’ll be able to enjoy all the power of DirectX 12 games as soon as they are available.
http://blogs.msdn.com/b/directx/archive/2014/03/20/directx-12.aspx

But feel free to correct me.

 

[Malo]

Over 80% definitely implies the majority of current AMD and NV GPUs are 100% DX12 capable.

So all GCN, and Kepler/Maxwell at least, most likely Fermi as well as reported.

 

[liquidboy]

DX 11.2 will work on DX 11.1 hardware too. The diference is that not all features are available! But can I say a card without those features supports DX 11.2??

Kepler for instance, it has no Tier2 support. Can I claim this card supports DX 11.2? I think not!

Question is: To use DX 11 you need DX 11 hardware support, and to use DX 11.2 you need DX 11.2 hardware support. Yet Microsoft claims 80% of all currently sold cards will support DX 12.

I do not doubt new features in DX 12 will eventualy require specific hardware that not all (or even any) current cards support. But with current claims I doubt that will happen on the first DX 12 release. Maybe on future revisions (that may appear at almost the same time as DX 12).

From the DirectX developers blog:

Q: Should I wait to buy a new PC or GPU?
A: No – if you buy a PC with supported graphics hardware (over 80% of gamer PCs currently being sold), you’ll be able to enjoy all the power of DirectX 12 games as soon as they are available.
http://blogs.msdn.com/b/directx/archive/2014/03/20/directx-12.aspx

But feel free to correct me.

SW/Shader fallback is fine, but I prefer HW(fixed function or what not) delivering my features ... I'll wait for FULL graphics HW to provide me FULL Dx12 experience.