Cycles slow render start with GTX 2070 #60576

New Issue

jan bauer · 2019-01-16T21:20:06+01:00

jan bauer commented

2019-01-16 21:20:06 +01:00

System Information
Operating system: Windows 10
Graphics card: RTX 2070

Blender Version
Broken: 8ba86020cc (but both 2.80 and 2.79 buildbots have the bug
Worked:

Short description of error
When rendering some scenes, Cycles takes more than 2 minutes to start the first tile. It happens often on the classroom scene, some scene are not hit by the bug (like bmw and barcelona)

Exact steps for others to reproduce the error
Open the classroom scene (from https://download.blender.org/demo/test/cycles_benchmark_20160228.zip) with latest buildbots and hit F12. Most of the time, only the first render has the bug, the following ones are ok. The bug is random, so sometime it starts directly.

**System Information** Operating system: Windows 10 Graphics card: RTX 2070 **Blender Version** Broken: 8ba86020cc50 (but both 2.80 and 2.79 buildbots have the bug Worked: **Short description of error** When rendering some scenes, Cycles takes more than 2 minutes to start the first tile. It happens often on the classroom scene, some scene are not hit by the bug (like bmw and barcelona) **Exact steps for others to reproduce the error** Open the classroom scene (from https://download.blender.org/demo/test/cycles_benchmark_20160228.zip) with latest buildbots and hit F12. Most of the time, only the first render has the bug, the following ones are ok. The bug is random, so sometime it starts directly.

jan bauer commented

2019-01-16 21:20:06 +01:00

Added subscriber: @janb-1

Brecht Van Lommel commented

2019-01-17 16:08:12 +01:00

Added subscriber: @brecht

Brecht Van Lommel commented

2019-01-17 16:08:12 +01:00

I can't reproduce the problem.

I assume you are using GPU rendering, and the problem does not happen with CPU rendering?
What shows in the render progress info text when it is stuck?
Has the problem always existed with this GPU, or did it work better before?

I can't reproduce the problem. * I assume you are using GPU rendering, and the problem does not happen with CPU rendering? * What shows in the render progress info text when it is stuck? * Has the problem always existed with this GPU, or did it work better before?

Brecht Van Lommel changed title from ~~regression - Cycles render very slow with latest buildbots~~ to Cycles slow render start with GTX 2070

2019-01-17 16:08:42 +01:00

Gavin Scott commented

2019-01-17 19:35:54 +01:00

Added subscriber: @GavinScott

Gavin Scott commented

2019-01-17 19:35:54 +01:00

I saw something like this today (on current 2.80 build, Windows 10, Nvidia 1060 6GB)) based on the scene in this discussion about CPU+GPU tile differences:

https://blenderartists.org/t/gpu-rendering-issue-tiles-rendering-different-colours/1142774/18

The .blend in that thread, when opened in 2.80 and hitting F12, sits for 90 seconds at Rendering progress 0% with no rendering progress messages having been displayed at the top of the screen. Stdout contained:

GPUFrameBuffer: framebuffer status GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT

So I wonder if this is a timeout talking to the GPU for some reason? The same .blend starts the render pre-processing immediately in 2.79 builds ('a' and recent but not current) and does not produce the GL_ message.

I saw something like this today (on current 2.80 build, Windows 10, Nvidia 1060 6GB)) based on the scene in this discussion about CPU+GPU tile differences: https://blenderartists.org/t/gpu-rendering-issue-tiles-rendering-different-colours/1142774/18 The .blend in that thread, when opened in 2.80 and hitting F12, sits for 90 seconds at Rendering progress 0% with no rendering progress messages having been displayed at the top of the screen. Stdout contained: GPUFrameBuffer: framebuffer status GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT So I wonder if this is a timeout talking to the GPU for some reason? The same .blend starts the render pre-processing immediately in 2.79 builds ('a' and recent but not current) and does not produce the GL_ message.

jan bauer commented

2019-01-17 20:01:12 +01:00

In #60576#601582, @brecht wrote:
I can't reproduce the problem.

I assume you are using GPU rendering, and the problem does not happen with CPU rendering?

I didn't test cpu rendering, it happens randomly also with GPU. I tried 10 times with CPU, it always started directly.

What shows in the render progress info text when it is stuck?

it says "updating shaders"

Has the problem always existed with this GPU, or did it work better before?

it's a new problem, it never happens on 2.79b, and I think something like november, the bug wasn't there (I remember benchmarking classroom around that time, but don't have a build anymore and it was with another GPU.)

> In #60576#601582, @brecht wrote: > I can't reproduce the problem. > > * I assume you are using GPU rendering, and the problem does not happen with CPU rendering? I didn't test cpu rendering, it happens randomly also with GPU. I tried 10 times with CPU, it always started directly. > * What shows in the render progress info text when it is stuck? it says "updating shaders" > * Has the problem always existed with this GPU, or did it work better before? it's a new problem, it never happens on 2.79b, and I think something like november, the bug wasn't there (I remember benchmarking classroom around that time, but don't have a build anymore and it was with another GPU.)

Brecht Van Lommel commented

2019-01-21 17:15:16 +01:00

Does it still happen with the latest builds?

Are you using a Threadripper or Ryzen CPU? We recently fixed an issue a bit like this for them.

Does it still happen with the latest builds? Are you using a Threadripper or Ryzen CPU? We recently fixed an issue a bit like this for them.

jan bauer commented

2019-01-27 19:56:21 +01:00

just tested with todays build, the bug is still there when using cuda rendering and a i7 7700K.

jan bauer commented

2019-02-26 20:39:16 +01:00

Changed status from 'Open' to: 'Resolved'

jan bauer closed this issue

2019-02-26 20:39:16 +01:00

jan bauer self-assigned this 2019-02-26 20:39:16 +01:00

jan bauer commented

2019-02-26 20:39:16 +01:00

the bug is gone since some weeks now, don't know why, but resolved.

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Cycles slow render start with GTX 2070 #60576