Direct3D feature levels discussion

[DmitryKo]

Isn't it the case that we still don't know how many UAV's these GPU's support

No, we don't. We only know the limits set by the API.

UAVs are essentially descriptor heaps, so it depends on memory pointer sizes, number of descriptor table entries, and machine instruction formats. These are low-level implementation details that can only be known from the ISA document, which Nvidia did not release to public.

we know for a fact it's misrepresenting it for at least Maxwell 2 which is showing 64 slots in dxcapsviewer but we know supports RB tier 2 and therefore MUST be full heap.

We have 3 conflicting versions on the number of UAVs for the Resource Binding tiers 1 and 2:

1. https://forum.beyond3d.com/posts/1834016/ - 8-64 on Tier 1, 64 on Tier 2
This is from page 39 of Intel IDF2014 presentation GVCS005 - Microsoft* Direct3D* 12: New API Details and Intel Optimizations

2. https://forum.beyond3d.com/posts/1829887/ 8 on Tier 1, 64 on Tier 2.
This is from March GDC2015 presentation http://channel9.msdn.com/Events/GDC/GDC-2015/Advanced-DirectX12-Graphics-and-Performance 6:40-9:30
It's also where Max claims these 39%, 44%, and 17% of all D3D12 cards for the three RB tiers.

3. https://forum.beyond3d.com/posts/1834185/ 64 on Tier 1, full heap on Tier 2.
This is from April 2015 pre-release Windows 10 SDK https://msdn.microsoft.com/en-us/library/windows/desktop/dn899127(v=vs.85).aspx

[EDIT] On April 25, MSDN has been updated with 8 UAVs on Tier 1 (64 for FL 11.1 and higher) and 64 on Tier 2.

If 64 then they need to be dropped back down to Tier 1 and thus lose full DX12_0 compliance.

There is no such thing as "full DX12 compliance".

 

[killeak]

Now that everybody can download and build apps using the beta SDK we can see what the hardware reports... So in my PCs I got this

Kepler: is Binding Resources Tier 2, and Tile Resources Tier 1.
Haswell: is Binding Resources Tier 1, Tile Resources Tier 0 (0 means no support)
Maxwell: not sure yet, I only have a 980m but hybrid graphics is not supported yet, so I can only create a device in the intel hd4400.

Now if you don't trust me, you can download the SDK and build something to get the feature support for each hw, you just need to create a device and call CheckFeatureSupport

 

[pjbliverpool]

Now that everybody can download and build apps using the beta SDK we can see what the hardware reports... So in my PCs I got this

Kepler: is Binding Resources Tier 2, and Tile Resources Tier 1.
Haswell: is Binding Resources Tier 1, Tile Resources Tier 0 (0 means no support)
Maxwell: not sure yet, I only have a 980m but hybrid graphics is not supported yet, so I can only create a device in the intel hd4400.

Now if you don't trust me, you can download the SDK and build something to get the feature support for each hw, you just need to create a device and call CheckFeatureSupport

Kepler is Binding Resources Tier 2? Wow, ok my table is way off then. Not quite sure how it qualifies for Tier 2 with only 8 UAV slots though unless dxcaps viewer is reporting it wrong.

 

[iroboto]

Now that everybody can download and build apps using the beta SDK we can see what the hardware reports... So in my PCs I got this

Kepler: is Binding Resources Tier 2, and Tile Resources Tier 1.
Haswell: is Binding Resources Tier 1, Tile Resources Tier 0 (0 means no support)
Maxwell: not sure yet, I only have a 980m but hybrid graphics is not supported yet, so I can only create a device in the intel hd4400.

Now if you don't trust me, you can download the SDK and build something to get the feature support for each hw, you just need to create a device and call CheckFeatureSupport

Lol I fell asleep installing VS2015 to get the d3d12 Libs. I should read Better though I don't see how vs2015 has to do with obtaining win10 SDK.

 

[killeak]

Lol I fell asleep installing VS2015 to get the d3d12 Libs. I should read Better though I don't see how vs2015 has to do with obtaining win10 SDK.

In theory, you need VS2015 CTP 6 to build Windows 10 SDK apps (and d3d12 apps). And is important to note that you need CTP 6. There is a update 5 beta for VS2013 that you can also use, but you won't have the graphics debug tools for D3D12.

 

[Ryan Smith]

Now that everybody can download and build apps using the beta SDK we can see what the hardware reports...

If you happen to get around to releasing binaries for that, I would be most grateful...

 

[Nemo]

.

 

[DmitryKo]

Direct3D 11.3 documentation is available:
https://msdn.microsoft.com/en-us/library/windows/desktop/dn914596(v=vs.85).aspx

 

[pjbliverpool]

.

So much contradictory information, I don't know what to think anymore!

 

[iroboto]

Take it from the lake directly. I'm sticking with d3d12 APi I and dxdiag.

 

[DmitryKo]

So much contradictory information, I don't know what to think anymore!

I see no contradiction. They could have said "Tier 1 or Tier 2", since some parts are built with GCN 1.0 chips which only support Tiled Resources Tier 1.
HD7790 does support Tier 2 though, since it's built with Bonnaire XT.

 

[iroboto]

Welp, you guys are going to need to help me out here. I'm running a Geforce 660. I installed the latest drivers here is a quick screen cap of my debug. @killeak can you post your results?

 

[DmitryKo]

I'm running a Geforce 660.

Resource Binding Tier 3 and Tiled Resources Tier 3 on Kepler? I don't think it's correct.

Can you run dxcapsview.exe to veriry the GTX680 screenshot above?

 

[Ryan Smith]

And which specific drivers are those? 349.90?

 

[iroboto]

Can you run dxcapsview.exe to veriry the GTX680 screenshot above?

'

And which specific drivers are those? 349.90?

Yes.

I can't quite explain my debug yet. So I was hoping someone could help out. I'll need to look further into what's going on. But I think I've found something.

I select which -sdk- I want when I write my code. I select my SDK, and I select the driver type which I've chosen 'WARP'. I'll mess around with Driver settings and report back.
edit: anything but WARP will not run. It needs to be warp to use D3D12.

Notice how it reports my card differently under WARP in DXcaps

 

[Ryan Smith]

WARP is Microsoft's software renderer. You don't want to be selecting that.

 

[DmitryKo]

Double-check D3D12CreateDevice - you need to request hardware device and feature level 11_0, since Kepler does not support 11_1, and make sure to disable the debug layer.

 

[iroboto]

WARP is Microsoft's software renderer. You don't want to be selecting that.

Lol. Haha. I such a noob. Yea I'll try to get d3d_driver_hardware working.

 

[iroboto]

Double-check D3D12CreateDevice - you need to request hardware device and feature level 11_0, since Kepler does not support 11_1, and make sure to disable the debug layer.

Will do!

 

[iroboto]

Updated: I am correctly projecting the right values now. So I'm going to try to make an app of it. Is this something you actually still need Ryan? If so, request some features, I'll see what I can do.