Blender 2.78.5/2.79 - Cannot switch to OpenCL render.
Closed, ArchivedPublic

Description

System Information
Windows 10 Home 64 bit Build 14393.

GPU is an AMD R9 390 running on an older Crimson driver (16.7.1) because of stability reasons.

Blender Version
Broken: 2.78.5 4e22e24 and 2.79 248bba81e7a
Worked: 2.78c e92f235283

Short description of error

I can't change the Cycles Compute Device to OpenCL and use my GPU for rendering. Earlier versions work fine. I want to use these versions because of the Principled BSDF shader but it's not really of any use if I'm stuck with CPU render.

Let me know if you need anymore info.

Screenshot: http://i.imgur.com/8TDZVSo.jpg

Details

Type
Bug
SA (MangoJam) edited the task description. (Show Details)
SA (MangoJam) edited the task description. (Show Details)

For Blender 2.79 we enabled more features in OpenCL to be on par with CUDA, but this also means we also require a recent AMD driver versions to have it all working correctly. Is upgrading to the latest driver really not an option?

Ah, I see. The reason I don't update is because of a problem I've had, twice actually. After the drivers were installed and the the BIOS showed up the screen would keep turning on and off and I couldn't get the security options to show. Then I got the idea to take out my GPU and switch my display to the CPU and rollback the driver which worked. This happened once when I manually updated and the second time when Windows Update was being too efficient. It was just a pain and achieved nothing.

I'll try updating again since I do really want to use the new shader and if OpenCL is on par with CUDA now that's just icing on the cake.

Now that I think about it it might have been a driver conflict, even though the installer said it was removing the old one, I'll remove current drivers manually and then update.

Thanks for the info!

Sergey Sharybin (sergey) closed this task as "Archived".Tue, Jul 18, 10:22 AM
Sergey Sharybin (sergey) claimed this task.

This is likely a result of rB1f0998b. The reasoning behind that commit is:

  • We did lots of changes to Cycles OpenCL to bring performance up on AMD GPUs.
  • Those changes made older drivers to work unreliably, often producing render artifacts and crashing.
  • Those older drivers are not supported by AMD.
  • There is no simple workaround to make those drivers to work.

So instead of investing unreasonable amount of time trying to workaround unsupported platform (which would likely cause performance loss on a newer driver/cards) we decided to stop supporting those: performance wise and feature wise we can't bring Cycles on older hardware/drivers more further than 2.78 release anyway.

So thanks for the report, but we can't make such configurations to work with Blender currently.

P.S. This change is listed in the release logs there https://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.79/Cycles#OpenCL

I understand. Thanks for the reply; I'll just try and get the driver to work.