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Maniphest T52107

Color management difference when using multiple and different GPUs together
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Description

System Information
Windows 10 64-bits
Intel Core i7-2600K
CUDA Rendering with GTX 560 Ti (sm_21) and GTX 780 (sm_35)

Blender Version
Broken: latest builds from Blender Buildbot, GraphicAll.org, and my own compiled builds (all of them 2.78.5)
Worked: official 2.78.1 release

Short description of error

I tried to use my older GTX 560 Ti with my GTX 780 to get faster renders, but I encountered this strange behavior when combining them: Picture here, Another example
I thought that the different CUDA kernels (sm_35 and sm_21) were the cause of this weird tiling effect. However, this does not happen when I use only one GPU at a time (and I get exactly the same results for both GPUs, no problem).

May have something to do with color management when using multiple GPUs, the problem disappears when I mute the Image texture node here:

rouleaustarwars.blend1 MBDownload

Original post @Blender StackExchange

Revisions and Commits

rC Cycles
rCebe981d93274 Fix T52107: Color management difference when using multiple and different GPUs…
rB Blender
rB4bc6faf9c838 Fix T52107: Color management difference when using multiple and different GPUs…

Related Objects

Event Timeline

Maxime Michel (maximemichel) renamed this task from Hue difference when using multiple and different GPUs together to Color management difference when using multiple and different GPUs together.Jul 18 2017, 2:12 PM
Maxime Michel (maximemichel) created this task.
Brecht Van Lommel (brecht) added subscribers: Stefan Werner (swerner), Brecht Van Lommel (brecht).Jul 18 2017, 2:36 PM

@Stefan Werner (swerner), I'm guessing this is due to rBec25060a05e3: Unlimited number of textures for Cycles, mixing cases with bindless texture support and not. Not sure if there's a good way to make this work.

Brecht Van Lommel (brecht) lowered the priority of this task from 90 to Normal.Jul 18 2017, 2:40 PM
Stefan Werner (swerner) added a comment.Jul 19 2017, 2:02 PM

The attached scene is missing its textures. Can you please pack them and upload it again?

Stefan Werner (swerner) added a comment.Jul 19 2017, 2:31 PM

@Brecht Van Lommel (brecht) You're probably right. I think it needs to use the same texture IDs for all CUDA architectures and then map back to SM_2x on the kernel side. I'll go dig out my GTX 460...

Maxime Michel (maximemichel) added a comment.Jul 19 2017, 2:54 PM

Sorry I forgot to pack the textures indeed, should be okay now:

rouleaustarwars.blend8 MBDownload

Stefan Werner (swerner) claimed this task.Jul 20 2017, 9:19 AM
Stefan Werner (swerner) changed the task status from Unknown Status to Resolved by committing rB4bc6faf9c838: Fix T52107: Color management difference when using multiple and different GPUs….Jul 20 2017, 10:03 AM
Stefan Werner (swerner) added a commit: rB4bc6faf9c838: Fix T52107: Color management difference when using multiple and different GPUs….
Stefan Werner (swerner) added a comment.Jul 20 2017, 10:04 AM

@Maxime Michel (maximemichel) if you could please verify that this is fixed with the upcoming automated builds.

Maxime Michel (maximemichel) added a comment.EditedJul 20 2017, 11:45 AM

I can't get the kernel to be compiled :

ptxas fatal   : More than 128 textures used in entry function 'kernel_cuda_branched_path_trace'

Full log here

Steffen Dünner (SteffenD) added a subscriber: Steffen Dünner (SteffenD).Jul 20 2017, 11:52 AM
In T52107#447031, @Maxime Michel (maximemichel) wrote:

I can't get the kernel to be compiled :

ptxas fatal   : More than 128 textures used in entry function 'kernel_cuda_branched_path_trace'

Same here. Win10 x64

Stefan Werner (swerner) added a comment.Jul 20 2017, 1:14 PM

Thanks, will take another look. Give me a couple of minutes.

Maxime Michel (maximemichel) added a comment.Jul 20 2017, 1:30 PM

Will test your new commit ASAP ;)

Stefan Werner (swerner) added a comment.Jul 20 2017, 1:41 PM

Should be working in c1ca3c8.

Maxime Michel (maximemichel) added a comment.Jul 20 2017, 3:20 PM

Seems to be working fine now! Thanks a lot ;)

Sergey Sharybin (sergey) added a commit: rCebe981d93274: Fix T52107: Color management difference when using multiple and different GPUs….Jul 25 2017, 12:08 PM