Unity Editor - from version 2019 on is killing my CPU

Hi everyone,

I'm facing a bad issue on my PC.
Working with a version higher than 2018, a few seconds after I play a scene ( empty scenes too ) the CPU temperature rises up to 83°C and the CPU fan seems like a plane just before take off.

The workaround is to use 2018.x.x LTS that is great as well, but I'd like to benefit from the new features in the future.

I'm installing all the new version as soon as they're available to find out if it has been "fixed", with no success until now.

Any idea for a possible cause?

2 different PCs affected

- Intel i7 3ghz 8-core + 16 GB RAM (currently using this)
- AMD Ryzen 5 3.6ghz 4-core + 8 GB RAM

 

Try using the profiler on the editor, and see what Unity is busy doing.

 

I've tried, obviously the graph shows high values on "other". Not so helpful in my case.

 

Hi Martin,
thanks for your suggestions.
I'll try to better understand Profiler and test as soon as I can, consider that I'm a self-teaching beginner at Unity and I'm not so expert on what to look for with the Profiler. Also I've just a few seconds for troubleshooting before the CPU starts its nuclear fission

Done both for playmode and editor. Is there a way I can give you the data binaries?

 

Hi @MartinTilo
profiler data uploaded (playmode + editor).
About the Interaction Mode it already was on Default, changed to Monitor Refresh Rate but nothing seems to change

Thanks

 

@MartinTilo I just wanted to point out that the Interaction Mode setting is not documented in the Unity manual for version 2019.3. I ended up here because I was trying to find a description for what exactly this setting does. Can you try to get a description added to the manual?

 

Hi Martin, thanks for the time you gave to me, but unfortunately all of these advices didn't lead to a solution to my problem, cpu still on 50% when in play mode and temperature > 80°C.
The weird thing is that this happens on 3 different PCs now. I bought a new one (the intel i7 + 16GB) some months ago as I thought Ryzen 4-core + 8GB could be a bottleneck, but I just think I'll be stuck on 2018 for a while.

 

Hi everyone, just FYI I managed to solve this issue.
I found out that fan speed and CPU temperature was simply related to Intel Turbo Boost, so I went in power management settings and set CPU max speed to 99%. This solved for me, for Unity and other software too.
Probably, also with AMD CPU, the same setting would give the same effect.

 

Hello,

Im having the same problem, the fan is constantly ON full blast while unity is open, i cant understand it. Do the engineers at unity notice that the fan is on all the time while using the editor, is that ok with them? Do they want to burn out our fan and CPU? Did they even test Unity a little bit before releasing it to the public? I mean something like this is hard to miss!!

In using Unity 2021.2.17f1

As soon as unity opens the computer starts overheating, even if its just sitting there doing nothing, is that the default operation of Unity, to overheat peoples computer?

 

Laptop manufacturers would be pretty stupid to install a fan that can't handle spinning, and I don't know what temp you see but the 83C in the original post is well within the limits of a laptop. In fact it's very normal for a laptop to sit at 100C for long periods of time.

Below is an entry from Intel's FAQ that discusses overheating. Like it mentions a CPU is designed to throttle itself to reduce power consumption and thus heat output but if for some reason that fails the CPU will shut off the entire system. That your laptop isn't shutting off shows that it's working as intended.

Spoiler: Overheating Entry from Intel's FAQ

Here is a quote from Robert Hallock (Director of Technical Marketing) at AMD stating that a processor running in the up to 90C is typical and by design for Zen 3 (Ryzen 5000).

Spoiler: Robert Hallock on Zen 3

All of the above applies to desktops too. Go watch a hardware reviewer that shows temperatures like Linus Tech Tips and you'll see that Intel CPUs will hit 100C and only then will they start throttling themselves to reduce heat output.

I know it's easy to freak out at this kind of thing. I was worried when I first bought my 5950X and my heavy duty air cooler (Noctua NH-D15) was not reducing the temperature only to discover that it as soon as the temp went down the processor simply gave itself more power to go faster. It literally is overclocking itself.

 

What about my mental health, constantly listening to the fan, its hard to concentrate. Why is it necessary for unity to do that just by opening the program and not doing anything? Im pretty sure its shortening the life of my computer.

If you have a car and you constantly rev it to the red line it wont last long!

 

Sorry for digging up this thread but given it comes up on a google search for high CPU usage in editor...I thought I'd updated it with the solution to the high CPU I've seen today.

Using Unity editor 2021.3.18f1 with CPU sitting at roughly 50% with nothing playing.

Profiler seemed to show lots of CPU cycles being taken by Probuilder. Sure enough, without the Probuilder tab being open or at the front of a tab stack, CPU goes back to a 1-2%

Edit: Using Probuilder 5.0.6

 

today I got 100 celsius on my cpu (intel i7 12gen) red lights in the PC, so I immediatelly turned off unity 2022.2.10 from PLay mode