Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] Bug Reporting => [Max] Resolved Bugs => Topic started by: fobus on 2022-06-20, 08:07:20

Title: Low CPU usage with passes
Post by: fobus on 2022-06-20, 08:07:20

Every pass CPU going to 0% usage and this leads to overall usage nearly 50% of CPU power. I investigate that with adaptivity off this gaps going to shrink a bit but always there.
Is there any ways to avoid this behavior?

Title: Re: Low CPU usage with passes
Post by: rowmanns on 2022-06-21, 15:40:51

Hey,

Which version of Corona are you using?

Rowan

Title: Re: Low CPU usage with passes
Post by: maru on 2022-06-21, 17:24:59

Is it the same regardless if you render your image in very low vs high resolution? (like 640x480 vs 2560x1440)

Title: Re: Low CPU usage with passes
Post by: fobus on 2022-07-08, 11:25:23

No matter what size of image rendering it using only fraction of CPU power. Here is another example of this behavior.

Title: Re: Low CPU usage with passes
Post by: rowmanns on 2022-07-08, 13:43:58

Hi,

To me this looks like a side effect of bucket rendering.

You can disable it with the following and see if it helps to eliminate the issue..

The following should go into the string options rollout in the development/exprimental stuff rollout in the performance tab of render setup. You will need to enable the development mode through render setup -> system -> system settings
int progressive.boxScramblingPassLimit = 1000

Let me know how you get on.

Rowan

Title: Re: Low CPU usage with passes
Post by: tallbox on 2022-07-08, 13:55:21

Quote from: fobus on 2022-06-20, 08:07:20

Every pass CPU going to 0% usage and this leads to overall usage nearly 50% of CPU power. I investigate that with adaptivity off this gaps going to shrink a bit but always there.
Is there any ways to avoid this behavior?

On one of our old workstation the CPU has the same behaviour. It's going up and down especially after the render is finished (without the denoiser on); very strange

Title: Re: Low CPU usage with passes
Post by: maru on 2022-07-08, 14:51:28

Please try what Rowan suggested in his previous post:

1. Enable the development rollout: https://support.chaos.com/hc/en-us/articles/4528523195537
2. Paste this into the string options window:
int progressive.boxScramblingPassLimit = 1000

More info: https://support.chaos.com/hc/en-us/articles/4528609584017-String-options-

Afterwards please let us know if it changes anything or not.

Title: Re: Low CPU usage with passes
Post by: fobus on 2022-07-08, 15:53:00

Shure, this is exactly it. OMG

Title: Re: Low CPU usage with passes
Post by: rowmanns on 2022-07-08, 16:13:28

All right!

Well it's good news that we have narrowed it down to this. I hope for the time being you can use this as a workaround..

We have this issue logged, and I'll bring it up with our devs again and let you know when I have some more info.

Cheers,

Rowan

(Report ID=CRMAX-514)

Title: Re: Low CPU usage with passes
Post by: fobus on 2022-07-08, 16:20:20

It may be useful to know that switching off adaptivity (three adaptivшен switches) removes this issue too.

Title: Re: Low CPU usage with passes
Post by: rowmanns on 2022-07-08, 16:26:22

Quote from: fobus on 2022-07-08, 16:20:20

It may be useful to know that switching off adaptivity (three adaptivшен switches) removes this issue too.

I haven't tested that as a workaround myself. I would advise against disabling those three as it can cause some other unwanted behaviours. Using the string option is safe to do :)

Title: Re: Low CPU usage with passes
Post by: fobus on 2022-07-08, 16:29:04

Your workaround much better of course. Thank you and hope to see this issue fixed.

Title: Re: Low CPU usage with passes
Post by: rowmanns on 2023-06-07, 15:44:07

Hi,

We have fixed this bug in v10 RC2 :)

You can find it here: https://forum.corona-renderer.com/index.php?topic=38385.msg213583#msg213583

Please let me know if you continue to have issues!

Thanks,

Rowan