Author Topic: Empty scenes = High temperature  (Read 1870 times)

2021-04-27, 12:20:20

Ahmad Kouti

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Hello friends.

I have a problem and I tested with two CPUs.
My CPU temperature rises sharply in empty scenes, but this is not the case in crowded scenes.
I had this problem in all previous versions too.

Does anyone know the reason?

Thanks

2021-04-30, 15:26:02
Reply #1

maru

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There is no such thing as "too high temperature in X case". The CPU should maintain a reasonable temperature under full load, that's all.
 
If you are getting high temperatures in some specific cases, it only means that your CPU cooling is not effective and should be fixed.
If you are NOT getting high temperatures in other cases, it means that the CPU is not utilized in 100% in those cases.

So to answer your original question:
Does anyone know the reason?
The reason is inefficient CPU cooling.

Marcin Miodek | chaos-corona.com
3D Support Team Lead - Corona | contact us

2021-05-04, 15:36:17
Reply #2

Ahmad Kouti

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My CPU is AMD 3960x, I use good cooling and I know the normal range of temperature in different cases.
As I said, this problem occurs to me in some empty scenes, for example, the same scene in the V-ray render engine does not have such a problem, and I have done this test with the same scene.

Do you still think there is a problem with cooling?

Is there an option in Corona settings that the CPU is less active?
(Except Windows Task Manager)

Thanks
« Last Edit: 2021-05-04, 15:52:06 by Ahmad Kouti »

2021-05-04, 15:54:42
Reply #3

TomG

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Well, thing is it must be a problem with cooling, because Corona can't use the CPU more than its maximum, no matter what the situation. This just means that the empty scene in Corona is using all threads at 100% with no microsecond breaks, whereas other tests actually have some sort of microsecond breaks that probably are too short to show in monitoring software but still give a core a chance to cool a little.

But overall, this just means your CPU is being genuinely used at 100%, which it is intended to do, but cooling is not keeping it cool enough under those conditions.
Tom Grimes | chaos-corona.com
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2021-05-04, 16:02:51
Reply #4

Ahmad Kouti

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Thanks, I used a trick.

I put a plane behind the product and disable the reflections and ... for it.
The temperature returned to normal, but the rendering time increased slightly.


2021-05-04, 16:11:50
Reply #5

TomG

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Yep, non-empty scenes will always have things being moved to and from memory etc. which gives those little microsecond pauses while a core waits for data and gives it time to cool down. (But you still might want to consider the cooling solution, or any overclocking that is in place, because basically the CPU is getting too hot when it is utilized to "really 100%", which it should still be able to handle.... just in case something else pushes it that hard in the future, e.g. denoising is like this and really uses all the cores to max without any breaks)
Tom Grimes | chaos-corona.com
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2021-05-04, 16:19:29
Reply #6

Ahmad Kouti

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According to what you said, does having a bucket rendering option also help solve this problem?

2021-05-04, 16:39:50
Reply #7

TomG

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There isn't a problem to solve on the Corona side :) In fact, the more things that can use a CPU to 100%, the better, as the faster things will be. So truth is, it is better to be sure your CPU can keep itself cool properly at full load, because the more often it is at full load, the better it is.
Tom Grimes | chaos-corona.com
Product Manager | contact us

2021-05-04, 18:09:23
Reply #8

Ahmad Kouti

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2021-05-04, 18:19:44
Reply #9

maru

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Do you still think there is a problem with cooling?

Yes. With proper cooling, a CPU should not overheat in any scenario. Software cannot cause a CPU to overheat with proper cooling.
Another possibility (which still comes down to overheating) is overclocking. If your CPU is overclocked, I would advise reverting to the defaults. Too aggressive overclocking can cause overheating.
Marcin Miodek | chaos-corona.com
3D Support Team Lead - Corona | contact us

2021-05-04, 18:47:32
Reply #10

Ahmad Kouti

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I did not think about overclocking 👌, I had to check. Thank you for your time