Re:Intel Arc dGPU DirectX 12 feature level support confusion ?

LynxRufus · ‎05-12-2023

Hi,

I recently tried out a new, free game demo on steam based on Unreal Engine 5,

and using UE's new features like Lumen & Nanites. I also wanted to give it a try because it also has XeSS . unfortunately it's always crashing after launch, but that's another story for a separate thread.

however, because of it, and while starting to investigate what might be the cause for it crashing,

among other things,

I started researching directx 12 (ultimate) different feature levels,

and since Intel was always marketing Arc supporting "directx12 ultimate" , and speaking of features like variable rate shading, mesh shading, or sampler feedback,

I always thought it meant full Direct3D 12_2 feature level support, which is often meant when people are speaking of dx12 "ultimate" .

I was confused, when I found out today that on my win10 (22H2) system, tools like DxDiag report that only Direct3D feature level 12_1 is supported ?

the aforementioned specific new features are mandatory for D3D 12_2 feature level according to wiki eg., but also appear on the right side as 'optional features' across all d3d12 feature levels..

https://en.wikipedia.org/wiki/Direct3D#Direct3D_12_levels

It's confusing, but I guess what it could mean that if a GPU/driver supports only all mandatory features of 12_1 eg, it could still have some of the newer 12_2 features but maybe missing some other features of that tier that would be mandatory for "full" feature level 12_2 support?

to clarify, what I would like to know now:

do up-to-date versions of windows 10 support D3D 12_2 ? or is it now windows 11 exclusive?
for Intels dedicated Arc GPUs, is there full D3D12 feature level 12_2 support/compatibilty, hardware/driver wise ?
if it turns out it is 'only' DirectX12 Ultimate with D3D12_1 plus various extra features but not the full D3D12_2 feature set, what features are currently not supported?

ty in advance !

Stefan3D · ‎05-13-2023

Double-check with Microsoft DxCapsViewer

https://github.com/microsoft/DxCapsViewer/releases

LynxRufus · ‎05-13-2023

@Stefan3D while tools like gpu-z says it's DirectX 12(12_2) ,

and - if I google up 'arc a770 specs' - on sites like techpowerup it is listed with support for DirectX Ultimate (12_2),

and even shader model 6.6 (which would be 'optional' and no mandatory requirement for d3d12 12_2, as wiki tells me):

https://www.techpowerup.com/gpu-specs/arc-a770.c3914

the latter - SM 6.6 - seems to be a requirement for certain new features of Unreal Engine 5 however, or maybe I am missunderstanding it? :

https://docs.unrealengine.com/5.2/en-US/hardware-and-software-specifications-for-unreal-engine/#requirementsforue5renderingfeatures

eg. for Nanite Virtualized Geometry & Virtual Shadow Maps ..

just like dxdiag, DxCapsViewer (thx for the tip) report D3D Feature Level 12_1 .

and to be more precise, according to DxCapsViewer maximum supported Shader Model is 6.5 .

(I've attached the full dxview.log from DxCapsViewer here, since I am no longer able to edit the starting post it sems, which has the dxdiag & ssu log)

seems like it really is still 12_1 for now then, together with SM 6.5 and not 12_2 with SM 6.6 ..

Stefan3D · ‎05-14-2023

Review this article

https://devblogs.microsoft.com/directx/new-in-directx-feature-level-12_2/

"As for D3D_FEATURE_LEVEL_12_2 itself, the feature level is available through Windows Insider program, SDK and build version 20170 and later."

So it is indeed missing in Windows 10 (build 19045)

Regarding GPU-Z, the author explains it briefly in the tool tip on the main tab.

What does advanced tab -> DirectX 12 read?

LynxRufus · ‎05-14-2023

ty.

as expected it reads feature level 12.1 , shader model 6.5 (file attached)

I still just find it really confusing, and am wondering, if for someone with an Arc on that said SDK /insider build from 2020 would also see 12.1 then or 12.2 ,

and what the GPU-Z advanced tab (eg.) would read on an up-to-date windows 11 then...

btw, to conclude (because I'm about to give up wondering about all of it) , this is what Intel's own Arc control center reads (german localization, still found no way to force it to english) :

shader model 5.1 ..oompfh... 😉

Stefan3D · ‎05-14-2023

Some comments from the GPU-Z author which might have been useful as tool tip...

https://www.techpowerup.com/forums/threads/accurately-determining-hardware-supported-directx-level.283972/#post-4552164
Create a context and check feature levels. This will give you what the current system supports, not what the underlying hardware supports.

For GPU-Z I'm using a lookup table. No other way to report "DX12 capable: Yes" on Windows XP or Windows 7

https://www.techpowerup.com/forums/threads/why-gpu-z-show-amd-radeon-rx-6000-series-as-directx-12_1-compilance-instead-of-dx12_2.285437/#post-4609114

The result of Advanced Tab is still a live reading and apparently isn't supported to show "12.2" on Windows 10 yet

Hugo_Intel · ‎05-22-2023

Hello LynxRufus

Thank you for posting on the Intel Communities. I know that this topic regarding the Directx 12 Ultimate feature set support is important to you and we would like to provide some input on this.

Our Intel® Arc™ GPUs do support DirectX 12 feature level 12_2 (full feature set support), you can refer to the following article for more information:

Intel® Arc™ A-series Graphics Gaming API Developer and Optimization Guide

As for API restrictions at the OS level and in order to know whether all the features are available in Windows 10, it would be better to ask Microsoft about this since they will take care of adding the functionality if possible.

Best Regards,

Hugo O.

Intel Customer Support Technician.

Hugo_Intel · ‎05-25-2023

Hello LynxRufus

I see there are no further questions related to this topic. In this case, we will proceed to close this thread. feel free to open a new topic if you have further questions.

Best Regards,

Hugo O.

Intel Customer Support Technician.