Author Topic: Low CPU usage  (Read 2181 times)

2018-07-03, 18:28:54

PROH

  • Active Users
  • **
  • Posts: 1176
    • View Profile
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

2018-07-03, 18:38:42
Reply #1

cecofuli

  • Active Users
  • **
  • Posts: 1580
    • View Profile
    • www.francescolegrenzi.com

2018-07-03, 18:47:13
Reply #2

PROH

  • Active Users
  • **
  • Posts: 1176
    • View Profile
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?

2018-07-03, 19:10:35
Reply #3

Frood

  • Active Users
  • **
  • Posts: 1690
    • View Profile
    • Rakete GmbH
Could you attach that simple box scene?


Good Luck

Never underestimate the power of a well placed level one spell.

2018-07-03, 19:13:15
Reply #4

sprayer

  • Active Users
  • **
  • Posts: 794
    • View Profile
IR is not using 100% cpu, by default -1 thread.  Can you check temperature at cpu?

2018-07-03, 19:51:09
Reply #5

PROH

  • Active Users
  • **
  • Posts: 1176
    • View Profile
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.

2018-07-03, 20:23:43
Reply #6

sprayer

  • Active Users
  • **
  • Posts: 794
    • View Profile
do not forget to change thermal grease sometimes=)

2018-07-03, 21:18:40
Reply #7

danio1011

  • Active Users
  • **
  • Posts: 290
    • View Profile
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!

2018-07-03, 21:25:19
Reply #8

PROH

  • Active Users
  • **
  • Posts: 1176
    • View Profile
Thanks. Actually I'm looking at for a new PC - maybe a Threadripper.

2018-07-04, 06:24:54
Reply #9

danio1011

  • Active Users
  • **
  • Posts: 290
    • View Profile
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.