RPI CPU Temperature - Is yours overheating without your knowledge?

1

Hi All,

I just managed to get my Systeminfo CPU temperature chart working, and I have now realised that my RPI4 is running constantly over 80 degrees centigrade.

If I run these:

  vcgencmd measure_clock arm
  vcgencmd measure_temp
  vcgencmd get_throttled

I get:

frequency(48)=600169920
temp=85.2'C
throttled=0xf0006

frequency(48)=1629386752
temp=83.7'C
throttled=0xf0008

So, it is throttling and occasionally soft temp limit active.
My CPU hovers around 1-5% - really not stressed.

I have my RPI inside a case link . I don’t have any flans, so I guess I have airflow issues.

I never noticed this in the past, but basically my CPU is overheating - Reducing my system life and impacting performance, but not telling me about the issue.

I just ordered a passive heatsink, which I am confident will solve / help.

However, I am wondering how many others have the same issue and are not aware of it ?

2

I use the following full metal case and the CPU temperature is around 46°. Removing the SD card is slightly more difficult and it requires a small plier.

1 Like
3

Modern CPUs can survive temperatures above 80C, its not an issue, but as you found out, they began to throttle. This allows to limit amount of heat which needs to dissipate. If you have no cooling on your RPI, then it will throttle even with small load. The RPI 4 and especially 5 have big enough computing power to hit limit of how fast heat can be extracted from case.
First of all, if you don’t have it yet, look for a radiator. If you do have a radiator, look for bigger one. Active cooling (fan), will work best, but its also a dust collector over time. In principle, case linked by Lionello is quite good, because CPU radiator is connected with case allowing better transmission of temperature outside of the inferior. This is fairly common design for industrial computers, where its CPU and /or memory radiator is tightly connected with metal case.

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4

When I started with openhab I had the notorious ambition to run it without fan, tried different passive cases and sinks
 But I could never completely avoid that the Pi throttled from time to time.

Now with the Pi5 I use a fan, It almost never runs and completely eliminated the throttling problem.

1 Like
5

Thanks for the responses guys - So it seems that people who know about the overheating use a passive or active case to address this issue - this sounds totally reasonable to me!

However, really my post was how many people (like myself) were not aware, and as a follow up, how can we make them aware?

By default RPI os tells you on bootup if it is undervolted, why nothing about throttling?
It seems so fundamental - this should be baked in.

For the OH crowd, this could be added to the openhabian-config tool, or in UI on homepage by default (for example).

One final point, my passive heatsink case arrived today, now my CPU is stable at 57c. My old case is definitely yellowing from heat damage.

Cheers
Will