Corona Renderer Forum

General Category => I need help => Topic started by: CiroC on 2015-10-21, 14:34:47

Title: Decrease in performance
Post by: CiroC on 2015-10-21, 14:34:47
Yes, again the same problem.

Sorry to bring again this topic, but "more ram" is not the answer for this issue.

I opened a "old" scene to re-render and what is my surprise that my Rays/s are bellow 150 and after 40min my total rays are 93.

It is a the same machine, the same scene without a single change, no displacement. It is even worse because I am trying to render half the resolution that I rendered 2 months ago.

I am using a build from Sep 22 and the render doesn't move. I went back to the daily build I used, July 23, and the render starts with any problem.

Any suggestion of what the problem might be?

Title: Re: Decrease in performance
Post by: CiroC on 2015-10-21, 15:32:34
If it helps:

I compared the render time between the July 23 daily build and the August 7 daily build. Although the render with August 7 is fast, the July 23 is even faster.

And by fast I mean having 250K Rays/s after 1 pass and having 73k after 1 pass.
Title: Re: Decrease in performance
Post by: CiroC on 2015-11-04, 15:39:19
Back to this point.

Now that I have more time I did a couple of tests using the new 1.3 version and the 23rd July daily build.

The scene as loads of tress, grass and some heavy mesh. No displacement. 2880x1920 PT-PT

As you can see by the attachments the difference is substantial. My test was doing 1 render pass with both versions and I had to stop the render with the 1.3 Version because I wasn't going anywhere.

And I am facing this problem when: a) I increase the image size or b) when I start having more geometry.

That really concerns me because I do loads of exterior scenes and I notice a massive difference between the daily builds. One after the one I started to notice a decrease on performance. I don't believe that the answer is get more RAM, because if it works perfectly well with 23rd July daily build.

Do you have any suggestion to solve this issue?
Title: Re: Decrease in performance
Post by: Nekrobul on 2015-11-04, 16:29:33
Disable low thread priority.
Title: Re: Decrease in performance
Post by: CiroC on 2015-11-04, 18:31:56
Disable low thread priority.

Good point Nekrobul. I will give a try :)

And thanks for your reply.
Title: Re: Decrease in performance
Post by: CiroC on 2015-11-04, 19:27:03
It worked. Something so simple.

:D

You sir are amazing.
Title: Re: Decrease in performance
Post by: Ondra on 2015-11-05, 13:35:30
Do you have any other compute-intensive tasks running? Are you doing something while the rendering runs?
Title: Re: Decrease in performance
Post by: yagi on 2015-11-05, 14:51:08
have similar or worse problem so pls, how did you disable "low thread priority" ?
Title: Re: Decrease in performance
Post by: CiroC on 2015-11-05, 15:28:36
Do you have any other compute-intensive tasks running? Are you doing something while the rendering runs?

No. I am just doing a render and takes ages, but by disabling the Low priority it works. And the problem happens on two different computers.

yagi go to the System tab under the System settings.
Title: Re: Decrease in performance
Post by: 3dboomerang on 2019-04-07, 09:06:13
is this still applyable in the latest version? I dont' see the option
Title: Re: Decrease in performance
Post by: Nekrobul on 2019-04-07, 13:12:38
is this still applyable in the latest version? I dont' see the option

You can do it manualy in Taskmanager.
Title: Re: Decrease in performance
Post by: Frood on 2019-04-08, 09:04:55
You can do it manualy in Taskmanager.

Don't think that this still applies to current versions. Corona thread priorities are independent from max threads and always use "low", regardless of the max process priority. You have to use string options in Development/Experimental setup to achieve this ("int system.threadPriority = Normal").

But as mentioned, if there is no other task using the CPU permanently it should make no difference in render speed and it's generally not a good idea to change priority if you want to work on a computer while rendering in the background.


Good Luck




Title: Re: Decrease in performance
Post by: 3dboomerang on 2019-04-09, 08:24:24
So they removed the option? WHY???
Title: Re: Decrease in performance
Post by: Frood on 2019-04-09, 08:39:32
Because usually you don't need it :) As mentioned, when there is no other task running which would need the CPU, all power goes to rendering anyway. Even idle priority would be enough. Do you have any issues where it would help to change the thread priority?


Good Luck


Title: Re: Decrease in performance
Post by: SairesArt on 2019-04-09, 14:12:44
So they removed the option? WHY???
I wouldn't make sense, if a render locked up the system.
Also, since rendering is time intensive you would expect to render while you browse, Run compositing software etc, without those softwares taking a performance hit (read, at the expense of rendering power)
Don't forget, the core value of Corona is simplicity and artist friendliness.

Just like setting cinebench or the corona benchmark to Realtime locks up even the screen but gives the best highscore. Technically an improvement, but practical? not so much. Obviously an extreme, but still.
Title: Re: Decrease in performance
Post by: maru on 2019-04-12, 10:50:56
It is still possible to change Corona thread priority using string options:
https://coronarenderer.freshdesk.com/support/solutions/articles/5000518663-string-options
Use at your own risk. ;)