Render resolution and speed

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Asticles
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Re: Render resolution and speed

Post by Asticles » Wed Mar 21, 2018 11:26 am

Thanks for taking care. So it's only on gpu side?

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Dade
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Re: Render resolution and speed

Post by Dade » Wed Mar 21, 2018 11:44 am

Woot:
prof.jpg
This is the timeline of GPU=>CPU memory transfers (in blue) and kernel execution (in green). Transferring 256MB (!) of frame buffer takes more than 46ms. It is about the same amount of time spent running GPU kernels so the rendering performance is cut in half or less. I will look for a solution.

P.S. CPU only rendering is something I have still to check.
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Asticles
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Re: Render resolution and speed

Post by Asticles » Wed Mar 21, 2018 12:19 pm

Awesome!

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Dade
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Re: Render resolution and speed

Post by Dade » Wed Mar 21, 2018 3:33 pm

I have implemented a new method to download the film in PATHOCL in order to optimize the transfer time when rendering at very high resolutions. The basic idea is to spend max. 1% of the time downloading the film from the GPU. It seems to works very well.

i7 3930k (6 cores, 12 threads) + AMD R9 290X + NVIDIA GTX980 (hybrid rendering enabled) with LuxMark Hotel scene.

At 1024x576:

Code: Select all

[Elapsed time:  60/0sec][Samples  531/0][Convergence 72.833084%][Avg. samples/sec  5.23M on 4973.4K tris]
At 4961x3508:

Code: Select all

[Elapsed time: 105/0sec][Samples   31/0][Convergence 0.000000%][Avg. samples/sec  5.21M on 4973.4K tris]
With the new method there isn't a difference.
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Dade
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Re: Render resolution and speed

Post by Dade » Wed Mar 21, 2018 3:36 pm

I did some test with PATHCPU too and it seems to work as expected.
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Sharlybg
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Re: Render resolution and speed

Post by Sharlybg » Wed Mar 21, 2018 4:05 pm

Dade wrote:
Wed Mar 21, 2018 3:36 pm
I did some test with PATHCPU too and it seems to work as expected.
HMMM this nice improvement :) .
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Asticles
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Re: Render resolution and speed

Post by Asticles » Wed Mar 21, 2018 6:01 pm

Great! Thanks.

Asticles
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Re: Render resolution and speed

Post by Asticles » Sat May 05, 2018 6:36 pm

Hi all,

I'm having also some performance issues with blender rendering at 4k resolutions on cpu (too big scene for my gpu).
Blender gets unresponsive (not responding), also setting refreshing time to 600s.

The only way I had to make it a bit better is to run the blender with windows 7 compatibility. I'm on windows 10.

As side note, rendering with cycles in that resolution doesn't make blender lags or be unresponsive.

Regards.

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Dade
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Re: Render resolution and speed

Post by Dade » Sat May 05, 2018 7:33 pm

Asticles wrote:
Sat May 05, 2018 6:36 pm
I'm having also some performance issues with blender rendering at 4k resolutions on cpu (too big scene for my gpu).
Blender gets unresponsive (not responding), also setting refreshing time to 600s.

The only way I had to make it a bit better is to run the blender with windows 7 compatibility. I'm on windows 10.
Check the amount of free RAM you have, you are probably swapping memory pages on the HD. You can use TILEPATH to reduce the amount of RAM required if the problem is the image size or you can run the rendering without Blender if the scene size is the problem.
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B.Y.O.B.
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Re: Render resolution and speed

Post by B.Y.O.B. » Sat May 05, 2018 7:45 pm

I can reproduce a certain slugginess with large film sizes, but no complete unresponsiveness.
It might be caused by the way the current render event loop is implemented in Python (just a while loop with 1/50 second sleeps or so), it might be better with a separate "thread". I'll take a look at it after v2.0 is out.

I have also noticed that BlendLuxCore uses a lot more RAM than Cycles in high resolutions, I opened an issue for this problem. Again, stuff for after v2.0
https://github.com/LuxCoreRender/BlendL ... issues/151
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