Page MenuHome

Can't force the detection of OpenCL devices
Confirmed, HighPublicTO DO

Description

Blender Version
Broken: maybe since 2.80?

Short description of error
At some point it was possible to force an OpenCL device to be picked up with CYCLES_OPENCL_SPLIT_KERNEL_TEST=1 in the environnement but it's apprently gone. I can see in opencl_util.cpp:861 that a flag exists for that very reason but it seems it was never implemented, could it be possible to set that flag to true with an option/env variable?

Event Timeline

I have to admit, this has annoyed me for the longest time as well, previously it was still possible to test opencl on nvidia using the cycles debug menu, but that has broken somewhere as well during one of @Jeroen Bakker (jbakker) 's refactors somewhere during 2.80.

which makes testing kernel changes more annoying than it should be , can we restore the functionality of the debug menu to either it's former glory or decide we don't care and remove the dead options from it

cc: @Brecht Van Lommel (brecht)

We no longer have the opencl mega kernel rB949ab753bb2e: Cycles OpenCL: Remove OpenCL MegaKernel
The kernel is splitted by default.

I don't understand the difference that this option would make. (We can't just bring the mega kernel back).

Aaron Carlisle (Blendify) changed the task status from Needs Triage to Confirmed.Feb 20 2020, 5:19 AM
Aaron Carlisle (Blendify) triaged this task as Low priority.
Aaron Carlisle (Blendify) changed the subtype of this task from "Report" to "To Do".
Brecht Van Lommel (brecht) raised the priority of this task from Low to High.Feb 20 2020, 1:03 PM
Brecht Van Lommel (brecht) edited projects, added Cycles; removed BF Blender.

Could you re-enable AMD 7870HD series for Cycles/OpenCL which were deprecated in Blender 2.78?

We are unlikely to bring back support for cards that were deprecated. I don't think the reason behind that decision has changed as the graphics card has not received driver updates for quite a while.

soulfire (vejn) added a comment.EditedWed, Mar 4, 5:58 AM

We are unlikely to bring back support for cards that were deprecated. I don't think the reason behind that decision has changed as the graphics card has not received driver updates for quite a while.

There was a glitch when rendering hair and microdisplacement with OpenCl on that card. Everything else worked.

I brought back the environment variable in D7202 to enable testing on unsupported hardware, leaving this ticket open though since the debug menu should still be either fixed or removed.