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Crash when Cycles rendering on Vega 64 (OpenCL)
Closed, ResolvedPublic


System Information
Operating system: Windows 10
Graphics card: AMD Vega 64

Blender Version
Broken: 2.80 Beta, 674d364af0b1, 2019-01-05
(example: 2.79b release)
(example: 2.80, edbf15d3c044, blender2.8, 2018-11-28, as found on the splash screen)
Worked: (optional)

Rendering animation of attached blend file in Cycles using AMD Vega 64. After a few minutes, Computer freezes, after a few seconds drops to black screen and then after a few more seconds the graphics card recovers but rendering stops. Running in Visual Studio 2017 cloned from github today (2018-01-05). Access violation exception occurs in amdocl64.dll (version 25.20.15002.58).

  • Steps to Recreate**

Render animation of attached blend scene on AMD Vega 64.

Attached micblend.blend and screenshot of exception/stack trace in from Visual Studio 2017.

This is my first time reporting a bug, please let me know if I can supply any further information.

Event Timeline

Sebastian Parborg (zeddb) triaged this task as Needs Information from User priority.Jan 31 2019, 1:37 PM

Do you have any issue if you run this GPU memtest program?

Additionally you can see if you GPU is stable with:

Do you have any problems with ?


I have run the LuxMark stress test (hotel lobby) with no issues and the kombustor test also with no issues.

On running the memtest, I get issues with the Random blocks test and none of the other ones. However, having looked online it seems like there may be a bug in the Random Blocks test.

One thing I have noted is while using 2.8 is that blend files I create initially seem to work but then after saving them a few times, they seem to eventually fail. Is the file becoming corrupted in some way maybe?

I have another example file which is failing if it would be useful to upload it to you?

Just to be sure, this is still a problem with the latest blender beta, right?


I have just downloaded the latest nightly build of 2.8 and it's still happening.

@Brecht Van Lommel (brecht) is there anyone at BI that could try to reproduce this?

I have just noted something interesting.

If I disable Motion Blur it renders fine. Not sure if this might be related to the issue.

Bastien Montagne (mont29) raised the priority of this task from Needs Information from User to Needs Triage by Developer.

@Jeroen Bakker (jbakker) I believe you are the current OpenCL guy? ;)

@Stephen Caulfield (blenderscuba) I have done a lot of changes to the OpenCL codebase since februari. I am trying to reproduce the issue, but could also be solved already. Would you mind to retest it with the latest blender build and latest AMD Drivers.

If it is still not working, could you add you systeminfo and clinfo to this bug report. That might help us to find out the issue.

This night I am rendering the scene on my system, to reproduce it.
Also can you run it with a memory monitor open. Could be related to memoryleak issue.

Bastien Montagne (mont29) triaged this task as Needs Information from User priority.Tue, Mar 19, 4:08 PM

Hi, tried again with today's build (blender-2.80.0-git.d47f827019f2-windows64) and latest AMD recommended drivers (19.1.1).

Got quite far through and then crashed. I have attached clinfo and sysinfo. I have another blend file which consistently crashes when Motion Blur is switched on that I can upload if that helps?

@Stephen Caulfield (blenderscuba) Could you attach the systeminfo that is created by blender? You can find it in the Help -> Save System Info.
Also have you checked the memory usage when rendering? On my system it also crashed, but expected a high memory usage at the time it crashed.

Memory usage of the scene when rendering animation. This graph is when rendering with CPU. I suspect that this is not an OpenCL related problem, but a memory leak in cycles or blender somewhere.

for every frame rendered 280 MB of memory is leaked

Error: Not freed memory blocks: 32, total unfreed memory 281.802979 MB
Mesh len: 1552 0x7f666f9dc338
CDMVert len: 11590400 0x7f6667400038
CustomData->layers len: 520 0x7f667abb3038
CDOrigIndex len: 2318080 0x7f6665806038
CDMEdge len: 13866240 0x7f6668000038
CustomData->layers len: 520 0x7f667abb32b8
CDOrigIndex len: 4622080 0x7f665b800038
CDMLoop len: 18432000 0x7f665a400038
CustomData->layers len: 520 0x7f667abb3538
CDOrigIndex len: 2304000 0x7f6669006038
CustomData->layers len: 520 0x7f667abb37b8
CDMPoly len: 6912000 0x7f6659c00038
BKE_mesh_recalc_tessellation len: 11520000 0x7f6654c00038
BKE_mesh_recalc_tessellation len: 2304000 0x7f6659006038
CustomData->layers len: 520 0x7f667abb2b38
dupli_mapalloc len: 8 0x7f666f9809f8
Mesh len: 1552 0x7f666f9e1738
CDMVert len: 11590400 0x7f6655800038
CustomData->layers len: 520 0x7f667abb3cb8
CDOrigIndex len: 2318080 0x7f6659406038
CDMEdge len: 13866240 0x7f6656400038
CustomData->layers len: 520 0x7f667abb3f38
CDOrigIndex len: 4622080 0x7f6677800038
CDMLoop len: 18432000 0x7f6652400038
CustomData->layers len: 520 0x7f667abb41b8
CDOrigIndex len: 2304000 0x7f6659806038
CustomData->layers len: 520 0x7f667abb4438
CDMPoly len: 6912000 0x7f6653800038
BKE_mesh_recalc_tessellation len: 11520000 0x7f664ac00038
BKE_mesh_recalc_tessellation len: 2304000 0x7f6654806038
CustomData->layers len: 520 0x7f667abb23b8
dupli_mapalloc len: 8 0x7f667ab31b38

Does not seem to be related to Object motion, but Object motion might double the effect. Issue is related to the beveled curve objects modifier. Would say:

"Memory leak when rendering a beveled curve in Cycles (only Blender2.80)"
Same memory leak appears when converting a curve to a mesh.
Seems like data of the evaluated tmp curve is not freed correctly.