Nvidia driver discussion

[zaps166]

Nvidia introduced new Vulkan SPIR-V compiler. Games using DXVK runs very slow with it (it can be disabled by using __GL_NextGenCompiler envvar).

Comparision [3840x2160, new vs old, disabled by envvar]:

• Tomb Raider 2013 main menu (ultra, but without tesselation): [7 FPS vs 40 FPS]
• NieR:Automata (some scene, full details, anti-aliasing off): [14.5 FPS vs 24 FPS]
• Sword Art Online Hollow Realization (Teleport Gate Plaza, full details, anti-aliasing off): [13 FPS vs 45 FPS]

Moreover:

• Tomb Raider 2013 scene with tesselation enabled is black (on old nvidia shader compiler graphics is corrupted, but visible)
• Sword Art Online Fatal Bullet scene is also black
• No performance difference on Unigine Heaven (DXVK) and Vulkan Examples (native Linux)

System information

• GPU: GeForce GTX 1080
• Driver: 396.18
• Wine version: 3.5
• DXVK version: 41132b8
• X11 Compositor: none/disabled
• Nvidia Force Composition Pipeline: enabled
• UseNvKmsCompositionPipeline: false

[doitsujin]

Well, the new compiler doesn't seem to be mature yet, don't use it for gaming with DXVK. Gathering some feedback might help them improve it though, and maybe uncover some new bugs in DXVK.

As for Tessellation in Tomb Raider 2013 not working properly, that is a DXVK bug I think.

@pdaniell-nv Could you keep an eye on this thread as well?

[pdaniell-nv]

Thanks for the heads up. I'll report back when I know more.

[xpander69]

Confirming its slow. GTA V usual 60-90FPS went to 20-35 FPS
Fixes GTA V sun issue though

396.18 with __GL_NextGenCompiler=1

396.18 with __GL_NextGenCompiler=0

Crysis 2 Tesselation got broken and performance went down

396.18 with __GL_NextGenCompiler=1

396.18 with __GL_NextGenCompiler=0

[vesim987]

@pdaniell-nv
There is example from The Witcher 3: https://streamable.com/0zgjl it is approximately 1/3 of performance of the old compiler.
Disabling Hull and Domain Shaders bumps up performance twice.

[pingubot]

Hi,

here are the issues i noticed so far:

My Card: GTX 970
Driver: 396.18

Crysis2:

• Tesselation is broken, see pictures of XPander
• Performance is minimum cut into half (gpu is fully loaded all the time)

Crysis3:

• Performance is minimum cut into half (gpu is fully loaded all the time)
• Didn't notice huge display issues yet, need to check

Battlefield Bad Company 2:

• I can enable MSAA now which crashes the game before
• Performance is 30% of the old driver and gpu load increased from ~60% to 100%
• Graphical issue, file attached:
• Enabling MSAA fixes those graphical issues
  

Battlefield 3:

• I can enable MSAA now which crashed the driver before
• Without MSAA the performance is unaffacted with the new driver. With MSAA 2x enabled the per is cut down to 30%, from ~ 100fps to ~30fps.

Far Cry 3:

• I can enable MSAA now which crashed the driver before
• Without MSAA the performance is unaffacted with the new driver. With MSAA 2x enabled the perf is cut down to ~36fps, from ~ 56fps.

Diablo 3:

• I can enable MSAA now which crashed the driver instntly before. But it is still not usable due to game freezes
• Performance is ~ 30 fps in the menu, was >100 fps before with MSAA disabled

Unigine Heaven.

• Doesn't launch for me anymore with Tesselation on, works with tesselation off
• No graphical issues detected so far, but was a super quick test

Many thanks !
Christian

[doitsujin]

It should be noted that not all of the games @pingubot mentioned are well-tested and some of them have known issues. I think only Crysis 2 and Unigine Heaven are expected to work properly.

[pingubot]

I haven't played all the games from beginning to the end (i did that for crysis 2, also a few hours into crysis 3, for the rest it is really less than 1 hour per game), but the things i mentioned are the things that have changed between the new and the old nvidia driver spirv compiler. So it is just to show the differences.

[pdaniell-nv]

@doitsujin Are there any SPIR-V work arounds in place for our old compiler? If so, they probably need to be removed for the new compiler in 396.18 and beyond.

[doitsujin]

@pdaniell-nv the only Nvidia-specific workaround in my compiler is adding an extra component to the coordinate vector for the OpImageSampleDref* instructions, which is legal in SPIR-V and doesn't actually seem to cause any issues with the new compiler.

With the exception of the aforementioned workaround, as well as GPUs which do not support the ShaderImageReadWithoutFormat capability, it generates the same code for all GPUs.

@pingubot What I'm trying to say is that you might simply be hitting undefined behaviour in some cases, which just happened to work for some reason with the old compiler.

[pdaniell-nv]

Ok, thanks. We're looking into the functionality and performance regressions described above.

[SveSop]

Using __GL_NextGenCompiler=1 (default) causes some sort of "black/green'ish" picture in Unigine benchmarks. This is with commit: 140dc27
On the other hand, there was a change vs. previous in Unigine Superposition with the setting __GL_NextGenCompiler=0 when it comes to lightreflections.. (Did not start with default =1 setting)

[pchome]

TW3:

• CPU usage: ~18%
• GPU usage: 100%
• Inverted colors (yellow == green)
• Texture glitches
• low fps (1/3, due to low cpu usage ?)
• log diff:
  old : warn: D3D11Device: No matching border color found for (1e+10,1e+10,1e+10,1e+10)
  new: warn: D3D11Device: No matching border color found for (1e+010,1e+010,1e+010,1e+010)

[pchome]

As an opposite effect to bugs in other games/applications I can report Just Cause 3 runs without issues (except green color dominated) now.

This is for wine-staging, game was launched from steam menu, no other settings touched.
Without DXVK it fully unplayable, a lot of glitches and missing textures.