DirectX 12 API Preview

[Ryan Smith]

Wait what? This was confirmed where? I understood the whole point of DX11.3 etc would be to bring DX12 features to older OSes, including 8 (especially considering 7 doesn't even support full 11.1, i doubt it would get 11.3 either)?

The purpose of 11.3 is to ensure feature parity between the high-level (D3D11) and low-level (D3D12) APIs on the same OS. What happens with 8 and 7 in particular remains to be seen, but adding features to a platform not getting D3D12 would at best be a secondary goal of 11.3.

Meanwhile, major feature additions often require a new version of WDDM. And as MS has already found out, backporting WDDM is problematic.

 

[fellix]

That's from a GDC'15 feature presentation.

So, as far as I'm getting it, the 12.0 level will apply to all DX11-class hardware (incl. the CPU overhead benefits), while the 12.1 specs is about exposing the new capabilities in Maxwell v2 and nextgen GCN ?

 

[willardjuice]

So, as far as I'm getting it, the 12.0 level will apply to all DX11-class hardware (incl. the CPU overhead benefits), while the 12.1 specs is about exposing the new capabilities in Maxwell v2 and nextgen GCN ?

Not quite, remember there's DirectX "software" and then there's "feature levels". What this means is DX12 "the software" will work on 11_0/11_1/12_0/12_1 capable gpus.

Wrt the slide, I think it means GCN 1.1/1.2 is 12_0 and Maxwell 2 is 12_1. Just a guess though.

 

[DmitryKo]

http://channel9.msdn.com/Events/GDC/GDC-2015/Advanced-DirectX12-Graphics-and-Performance
Advanced DirectX12 Graphics and Performance

• Date: March 4, 2015 from 2:00PM to 3:00PM
• Speakers: Max McMullen

DirectX12 enables next generation games to deliver better performance with greater flexibility and control. This technical session goes deep into the DirectX12 APIs you can use to reduce CPU rendering overhead, manage GPU resource usage more efficiently, and express the most cutting-edge 3D graphics possible across the spectrum of Windows 10 devices. Whether you are building a game for the phone, PC, or Xbox - you don't want to miss this talk.


http://channel9.msdn.com/Events/GDC/GDC-2015/Better-Power-Better-Performance-Your-Game-on-DirectX12

Better Power, Better Performance: Your Game on DirectX12

• Date: March 6, 2015 from 10:00AM to 11:00AM
• Speakers: Bennett Sorbo

Direct3D 12 enables new performance improvements for your game on Windows 10. Learn how to architect your game engine to best reduce CPU overhead, increase GPU efficiency, and improve frame-rate stability using the new Direct3D 12 API. Understand the fundamentals for building a fast-performing, efficient game engine on Direct3D 12 and where to find the best resources for diving deeper.


http://channel9.msdn.com/Events/GDC/GDC-2015/PC-Games-for-Windows-10

PC Games for Windows 10

• Date: March 6, 2015 from 1:30PM to 2:30PM
• Speakers: Chuck Walbourn

Windows 10 brings new features for developers targeting the phone, tablet and desktop PC gamers. In addition to DirectX 12 and improved access to modern features, there are better tools for developing, debugging, and profiling games. Learn how your new Windows PC games can take advantage of Windows 10 capabilities and get tips on making your current Windows games work great on Windows 10.

 

[Max McMullen]

Don't forget:

http://channel9.msdn.com/Events/GDC...s-Problems-with-your-Game-Using-DirectX-Tools

Solve the Tough Graphics Problems with your Game Using DirectX Tools

• Date: March 5, 2015 from 5:30PM to 6:30PM
• Speakers: Rudolph Balaz, Rong Lu, Jason Strayer

Great tools for debugging and profiling are critical to the success of your graphics engine. Microsoft regularly updates a set of great graphics tools in Visual Studio and Windows that enable you to build great games. Come to this talk to learn about our currently shipping features, the upcoming DirectX 12 toolset, and discuss future directions. This talk will highlight top graphics debugging and performance problems and map key features to help you address those problems.

Max McMullen
Direct3D Development Lead
Microsoft

 

[Kaotik]

http://linustechtips.com/main/topic...nd-nvidia-multi-gpu-configurations-confirmed/

MS Tech Support apparently confirms multi-GPU support between vendors. Though I wouldn't be surprised if they gave accidently wrong info/understood the question wrong

 

[Raqia]

An interesting post about the state of APIs and the origins of Mantle/Vulkan/DX12:

http://www.gamedev.net/topic/666419-what-are-your-opinions-on-dx12vulkanmantle/#entry5215019

 

[pjbliverpool]

Excellent post. It made many things much clearer.

 

[Dave Baumann]

Futuremark now has a DX11/Mantle/DX12 draw call throughput test:

http://www.pcper.com/reviews/Graphics-Cards/3DMark-API-Overhead-Feature-Test-Early-DX12-Performance

 

[gamervivek]

And AMD are better at it, what were the odds, heh.

Interestingly, AMD shows little to no scaling between the DX11 single threaded and DX11 multi-threaded scores with the API Overhead Feature Test, which gives credence to the idea that AMD's current driver stack is not as optimized for DX11 gaming as it should be. The DX12 results are definitely forward looking and things could shift in that area, but the DX11 results are very important to gamers and enthusiasts today - so these are results worth considering.

Explains AMD's poor results at lower resolutions even when their GPUs are on the leaner side, for example 7970 catching upto 780 as resolution goes up instead of the other way round.

 

[Scott_Arm]

And AMD are better at it, what were the odds, heh.

Mantle only has to support one hardware family.

 

[gamervivek]

They are doing better even in DX12.

 

[Jawed]

AMD's D3D11 performance is pretty shocking. I suppose one could say that GCN is an architecture designed for efficient APIs (consoles, D3D12...). And of course we have no idea whether that awful D3D11 overhead (and almost non-existent performance scaling with cores or multi-threaded techniques, which net NVidia upto ~2x performance) is impacting games.

At a given GPU architecture's clock rate (e.g. GCN at 1GHz) shouldn't the results be the same no matter which GPU is running?

 

[Jawed]

Excellent post. It made many things much clearer.

Seems I should have put that in my signature as that's the second time after I linked that post that it's been posted round here EDIT: oh, actually that's the first time, now I think about it - too many forums.

 

[Malo]

And their DX11 performance is going to continue to be a pain point still for years to come. It's not as if everything is suddenly going to be coded for DX12 once Windows 10 / DX12 is released.

 

[liquidboy]

The DX12 capabilities of your system (feature support)

 

[iroboto]

The DX12 capabilities of your system (feature support)

Hey liquid, what was the source of this?

 

[liquidboy]

Hey liquid, what was the source of this?

The DX12 msdn pages, I tweeted about it yesterday (when it went public) https://msdn.microsoft.com/en-us/library/dn903821(v=vs.85).aspx

 

[iroboto]

The DX12 msdn pages, I tweeted about it yesterday (when it went public) https://msdn.microsoft.com/en-us/library/dn903821(v=vs.85).aspx

oh LOL you drew the picture yourself. Okay thanks for the link. Will write up it up tonight.

 

[Andrew Lauritzen]

I do want to caution guys - Microsoft and Futuremark are *really not kidding* when they are telling you that this is not a useful benchmark for comparing GPUs to one another. They make zero effort to even do a consistent amount of GPU work, let alone anything representative. See the pcper overclocking results for instance, but the rabbit hole goes much deeper.

This benchmark is only useful for comparing how well different APIs work on a given system (CPU+GPU), not for comparing systems. The takeaway here is that DX12 (and Mantle) is clearly much better than DX11, on all hardware.