Slow GPU render #48062

New Issue

Well, it seems that Leandro has not packed textures. But I can confirm the problem with this scene "ExpositorQoolEvotution_V1.blend", both CPU and GPU (rendering without textures):

Blender 2.76b:
GPU (256x256): 03:21.47
CPU (32x32): 04:26:34

Blender 2.77:
GPU (256x256): 06:06.93
CPU (32x32): 06:51.67

The problem does not occur with BMW27.blend scene, it is almost the same time with 2.76b or 2.77 in BMW scene,

Kubuntu Linux 14.04 64 bits, GTX 960 4GB, i7 3770 Well, it seems that Leandro has not packed textures. But I can confirm the problem with this scene "ExpositorQoolEvotution_V1.blend", both CPU and GPU (rendering without textures): Blender 2.76b: GPU (256x256): 03:21.47 CPU (32x32): 04:26:34 Blender 2.77: GPU (256x256): 06:06.93 CPU (32x32): 06:51.67 The problem does not occur with BMW27.blend scene, it is almost the same time with 2.76b or 2.77 in BMW scene,

Leandro Oliveira commented

2016-04-06 03:52:55 +02:00

Same issue happened in another scene. And sorry, I forgot to pack textures.

Germano Cavalcante commented

2016-04-06 05:42:05 +02:00

Added subscriber: @mano-wii

Carlo Andreacchio commented

2016-04-06 05:57:12 +02:00

Added subscriber: @candreacchio

Carlo Andreacchio commented

2016-04-06 05:57:12 +02:00

Slowdown also occurs on the GTX580 Windows 7

Nacho Conesa commented

2016-04-07 20:41:24 +02:00

Added subscriber: @NachoConesa

Leandro Oliveira commented

2016-04-08 14:55:53 +02:00

Hi Aaron and Thomas. Another guy, sanjio666, at Blenderartists, had the same issue, and described it with more details: http://blenderartists.org/forum/showthread.php?396102-GPU-render-slow-in-2-77&p=3031794

Wolfgang Faehnle commented

2016-04-08 16:34:12 +02:00

Added subscriber: @mib2berlin

Wolfgang Faehnle commented

2016-04-08 16:34:12 +02:00

Hi, check file on:

Opensuse Leap 42.1 x86_64
Intel i5 3570K
RAM 16 GB
GTX 760 4 GB /Display card
GTX 670 2 GB
Driver 361.42

If I switch environment back to RGB 2.76b and 2.77a render with same render time (GPU).
If I add own environment map Blender 2.76b need about ~50% of render time compare to 2.77a.
This seams different error to the GTX 980Ti/TitanX problem.

Mib

Hi, check file on: Opensuse Leap 42.1 x86_64 Intel i5 3570K RAM 16 GB GTX 760 4 GB /Display card GTX 670 2 GB Driver 361.42 If I switch environment back to RGB 2.76b and 2.77a render with same render time (GPU). If I add own environment map Blender 2.76b need about ~50% of render time compare to 2.77a. This seams different error to the GTX 980Ti/TitanX problem. Mib

Sergey Sharybin commented

2016-04-09 00:07:50 +02:00

Added subscriber: @Sergey

Sergey Sharybin commented

2016-04-09 00:07:50 +02:00

Changed status from 'Open' to: 'Archived'

Sergey Sharybin closed this issue

2016-04-09 00:07:50 +02:00

Sergey Sharybin self-assigned this 2016-04-09 00:07:50 +02:00

Sergey Sharybin commented

2016-04-09 00:07:50 +02:00

This issue here is caused by the fact that you go from file saved in Blender 2.77 to Blender 2.76. This makes it so Cycles settings which were not explicitly changed to differ if some defaults changed. In the file from the original report it is World MIS which is responsive for the slowdown. MIS usually reduces noise, but doesn't go for free. If it's causes more slowdown that noise reduction you can disable it.

Thanks for the report, but it was an intentional change listed there https://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.77/Cycles#Settings

This issue here is caused by the fact that you go from file saved in Blender 2.77 to Blender 2.76. This makes it so Cycles settings which were not explicitly changed to differ if some defaults changed. In the file from the original report it is World MIS which is responsive for the slowdown. MIS usually reduces noise, but doesn't go for free. If it's causes more slowdown that noise reduction you can disable it. Thanks for the report, but it was an intentional change listed there https://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.77/Cycles#Settings

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Slow GPU render #48062