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i am newbie at Raspberry so maybe this question is stupid. Can RPi control CPU temperature by itself at desired point, for example 70°C? I started the RPi and tested the internet and played a movie and the CPU temperature rised to 80°C ... So, Is it possible to set the RPi to keep (automatically) the temperature set to, for example, 70°C, by reducing the CPU power or the clock?

Second, question...Does the rbp have any temperature guard that turns off the device when it reaches a critical temperature? Like desktop PCs.

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  • That's two questions. Please ask one at a time. – Chenmunka Mar 11 at 19:00
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"Yes" is the answer to at least one of your questions.

For a fuller understanding, you will need some background and explanation on how this works. The "official" documentation is a reliable source. In a nutshell: part of the RPi firmware contains code that implements a closed-loop thermal management system. This "guarantees" that performance/clock speed is reduced based on temperature sensors in the hardware.

Another way to look at it is this: You only need to consider cooling (fans/heatsinks/etc) if you need greater performance.

As far as what settings you can make, this will vary depending on the model of your hardware. I know that sounds vague, and possibly disappointing, but the RPi firmware is closed-source. In other words, if the RPi Foundation doesn't see fit to add it, then by and large it simply does not get added.

You could of course write some code to implement your own thermal management system, but it will not have full control. For example:

measure temp with vcgencmd measure_temp
if vcgencmd measure_temp ≥ my_temp_limit then
turn on the fan (or increase fan speed)

I feel the key here is to understand the following:

  • higher performance requires higher clock speeds
  • higher clock speeds beget higher chip temperatures
  • higher temperatures are ruinous to hardware (ref Arrhenius equation)
  • reducing thermal resistance (heat sinks, fans, etc) reduces chip temperature

And amidst all of this technical minutiae, don't forget that the simplest way to get more performance from any RPi is to turn it on its side: "mounting the Pi vertically can also help with heat dissipation, as doing so can improve air flow".


Edit: This Q&A may also be useful.

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The Pi will start throttling down frequency and voltages when the temperature exceeds 85°C.

Only the Pi3B+ has some temperature configuration with temp_soft_limit.

Better to add a heatsink, well ventilated case and if necessary a fan.

https://www.raspberrypi.org/documentation/hardware/raspberrypi/frequency-management.md

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  • I have RPi 3B 1.2v with original case... So in my case temp_soft_limit is unavailable... – Sahasrar Mar 11 at 16:05

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