for some reason i get often 100% cpu usage in IPR render, even though i set the IPR to not use all threads.
any idea?
this is new for me, i use latest v13 daily
this means i can hardly edit any while IPR is running
thanks
for info/help
Stefan
What OS, and what hardware, please? And can you share screengrabs of the settings, so we can double check what you have set 
Thanks!
win10, dual xeon 56 core, c4d 2024.5
default settings, denoiser for IPR off
also if i reduce the cpu usage settings for IPR it doesnt improve
i didn t have this in 12, but now in almost any bigger scene, i cannot even stop the the ipr render or close the vfb window(only after many tries)
the extreme cpu usage problem is ONLY when rendering IPR, not when rendering final images.
ok maybe i found it; the default -1 setting (one thread less than all possible threads) seem not to work anymore, also not -2,-3,-4…
what does work it seems is set the actual thread number, so i used 24 threads and now ipr usage is like expected and the gui doesnt stall anymore.
sadly i must say it isnt solved, the problem comes back after a time:
- even though i set cpu thread usage to 12(on a 56thread pc) it often uses 99% cpu power, it seems to ignore this setting
i also had the case where it did ignore the max IR resolution which i have at 1600px, still it did render more than 17xxpx
it seems the settings are party ignored, it is not related to once scene but many new and older, most time faster a time of rendering,
it is ONLY in IPR, fial render works fine.
somehow i have the feeling v13 has a very aggressive threading for the pr, this is counter productive. today i had to force kill a project, loosing 20 min of work, and not even that worked, the only way was to force restart the whole PC.
i hope you can solve it, Corona is great, but this problem is quite a pain.
Hey, the issue with IR threads limit not working should be resolved in the latest RC2.
thanks Ales,
i load this right away, RC2 seem to have some very good fixes!
Sure this is fixed for Mac version in RC2?
Still has 100& CPU on IPR.
Are you sure Corona is not set to not use all threads in IR? In which case, it should be using 100% Can you share a screengrab of that setting please?
Yep, that looks right. Do you experience lag or slowdown as mentioned earlier? (If not, then the reporting system saying the CPU is 100% in use is not a problem - only if it’s having an impact on responsiveness is it an issue). What OS are you using, and which version of Corona? Do you still see 100% usage (and lag) with threads set to something like -4? And what if you use the positive number as mentioned in an earlier post (so if you have 32 threads, setting “31” in there)? Thanks in advance for the extra info!
I experience such lag whole system freezes during IPR rendering. Has not been the case before.
Changing thread-numbers seem to fix nothing?
Sonoma 14.5 (23F79)
Version • 12 Update 1 (Release Candidate 2)
Build timestamp • Nov 14 2024 02:38:57
Cinema version • 2025.1.1 Cinema 4D
Why are you using an RC of Update 1, since it is out officially? Definitely be sure to be using the final official release You could also try the latest daily at https://forum.corona-renderer.com/ Chaos Corona 13 for Cinema 4D daily builds - Changelog #msg230037 - let us know if either of those builds still give you issues, as changing the thread numbers should make a significant difference (make it so Corona only gets 1 thread, ensure that things are a lot slower, then we know the number changes are working ).
Well, my guess it’s due to pure incompetence or post traumatic retardness. Will use latest and try it 
.
Sorry bothering you guys with stupid questions when I apparantly should check obvious stuff first.
Oh, not a stupid question, as it may still happen with the official release - but is worth running it juuuuuust to be sure Eliminates some small possibilities on the cause if we know for sure. Anyway, no question is ever a stupid question (except the unasked one, as then it never gets answered!). Keep on with the feedback and questions, please!
Are there any updates regarding the CPU usage at 100% both in IPR mode and render, and the consequent malfunctioning of the system with freezes, slowdowns, and stuttering of all windows, making it impossible to manage any Windows window or any program? I have tried both version 12 and version 13, but on my AMD 9950x, all this continues to happen. If I launch an interactive render window, or if I launch the render, the system freezes until the render is finished, making it impossible to work in other windows in the meantime or to use the interactive feature to manage and configure my scene with the creation of materials, lights, and effects, etc.
Sorry but… In this way, Corona Renderer is practically unusable, and I am just wasting my license time.
Are there any solutions or refunds available for users experiencing these issues?
+1
I’m on windows latest version 24h2
Latest Corona 12 update1
Amd r9 5950x
IPR takes a long time to start and when it does the system freezes and slowdown.
It’s very hard to work with
Hi, we have received some similar reports in the 3ds Max section: https://forum.corona-renderer.com/ Interactive rendering slows down.
The solution we are aware so far is installing the BETA Windows Update version by going to Windows 11 Settings > Windows Update > Windows Insider Program, and enabling the Beta Channel. I hope this helps!
If the above doesn’t help, you can also try the following:
- update your chipset driver
- update your BIOS
- disable core parking - remove parked status of cpu - Microsoft Q&A
- disable core isolation and virtual machine platform - https://www.makeuseof.com/windows-disable-two-virtualizations-game-performance-boose/
- go to BIOS and set CPU SoC voltage from the default 1.25V to 1.2V and Infinity Fabric (FCLK) to 2000 MHz
- change your power plan in Windows (try all available options, power saving, high performance, etc)
I’ve tried everything you’ve listed to do and absolutely nothing changes on my 9950x with Asus ProArt X870e. Guys, this way it is really impossible to use CoronaRenderer, and we’ve been in this situation since December 2024.
Kindly (I imagine it’s the same for everyone), try to resolve it shortly because we are in the third month where it is impossible to use the software correctly (which I love but alas, I’m now using alternatives like RedShift because I can’t block the PC every time).
I don’t want to be the bad cop in the situation, but until you solve it, at least offer us VANTAGE (hoping it doesn’t have these problems), a way to at least mitigate the problem for those of us who have these inconveniences and are trying in any way to stay here and help you to continue the experience with CoronaRenderer.
Have you tried installing the beta Windows Update? It is confirmed by multiple users as a fix to this.