Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: PROH on 2018-07-03, 18:28:54

Title: Low CPU usage
Post by: PROH on 2018-07-03, 18:28:54

Hi. After installing Corona v2 I noticed that my CPU slowly decrease to around 60-65% when doing a straight render. When I use IR it's around 100% just as it should. I've tested it with a simple scene on both max2014 and max2016, and the result is the same: at first render the CPU usage is 100%, but after that it slowly decreases.

I've tried several scenes with the same result :( Even a simple scene containing only 10 X 10 X 10 instanced boxes with a default corona mtl shows the same result (both pt and UHD).

Since IR works correct, I don't think it's my PC, but I honestly have no clue about what to do. Does someone have any advise?

PC: I7 3930k with 32Gb RAM

Title: Re: Low CPU usage
Post by: cecofuli on 2018-07-03, 18:38:42

Try to reset the scene with the Reset button.

Title: Re: Low CPU usage
Post by: PROH on 2018-07-03, 18:47:13

Thanks for your suggestion.

I did do that too. But it didn't help. I also tried manually to switch between render engines, and that didn't help neither :(

Anything else I could try?

Title: Re: Low CPU usage
Post by: Frood on 2018-07-03, 19:10:35

Could you attach that simple box scene?


Good Luck

Title: Re: Low CPU usage
Post by: sprayer on 2018-07-03, 19:13:15

IR is not using 100% cpu, by default -1 thread.  Can you check temperature at cpu?

Title: Re: Low CPU usage
Post by: PROH on 2018-07-03, 19:51:09

OK, looks like it's solved (for the moment at least). I unplugged the PC and vacuum cleaned it inside. And now it's working as it should, even with huge files :) It still decrease the usage slightly, but seems to be Stable around 95%.

Hope it stays that way :)

Thanks for everyone's help.

Title: Re: Low CPU usage
Post by: sprayer on 2018-07-03, 20:23:43

do not forget to change thermal grease sometimes=)

Title: Re: Low CPU usage
Post by: danio1011 on 2018-07-03, 21:18:40

I had that happen recently due to a failing AIO cooler.  I would have expected core speed to drop @ 87C but core AND usage dropped.  Weird.

If you are so close to overheating that cleaning filters makes the difference I’d consider looking into a better cpu cooler...just my two cents!

Title: Re: Low CPU usage
Post by: PROH on 2018-07-03, 21:25:19

Thanks. Actually I'm looking at for a new PC - maybe a Threadripper.

Title: Re: Low CPU usage
Post by: danio1011 on 2018-07-04, 06:24:54

Quote from: PROH on 2018-07-03, 21:25:19

Thanks. Actually I'm looking at for a new PC - maybe a Threadripper.

That’s what I have.  I highly recommend the Noctua for cooling.  I tried the Enermax AIO but wasn’t pleased.