RPi Compute module high temperature operation

You can use code like this to get the Temps internal to the chip:

vcgencmd measure_temp

Shows core temperature of BCM2835 SoC.

root@raspberrypi:~# vcgencmd measure_temp 
temp=42.8'C

From: RPI vcgencmd usage - eLinux.org

Clem

This is better, not only shows thermals, but also the  freq (so you can see if you are throttling for either heat or voltage):

2 sec readouts:

Scrolling:

while true; do vcgencmd measure_clock arm; vcgencmd measure_temp; sleep 2; done

Non-scrolling:

watch '(vcgencmd measure_temp; vcgencmd measure_clock arm)'

@ Pål Dahle

The module cannot have temps exceed 80C.

However, this range is the maximum for the silicon die; therefore developers should take into account the heat generated when in use and make sure this does not cause the device temperature to exceed 80°C.

At 80C the pi 3 throttles, at 85C all voltage and freq revert back to minimum defaults (for example, at 85C the Pi 3 reverts to 600 MHz). For under voltage, regardless of thermals, Pi 3 thottles/reverts to minimum voltage and freq.

When the Pi throttles/reverts to minimum freq and voltages, performance of the Pi is reduced/degraded as a result.

Here are some stock pi 3 benchmarks (A pi that overheats or is undervolted, will perform beneath the benchmarks, e.g., an undervolting/throttling Pi 3 may only pass at 3 Gflops on the linpack benchmark, indicating a computational performance degradation/loss of approx. 50%):

Sysbench (CPU prime number test) -validated run (passes if completed in 119 seconds or less)

Cpuburn-a53 (thermals and voltage test using neon Instructions) (passes if no throttling occurs, and can maintain thermals at 79C or lower)

Linpack Bench (CPU floating point computing power test, thermals and voltage test using neon Instructions) ( passes if results are 'PASSED'  at 6 GFLOPS (6 billion operations per second) or higher)

https://youtu.be/KuEZV0WsRLg?t=7m20s

Test your Pi/Pi 3, and resolve any voltage/thermal issues as needed:

............................................................

...........................................................

/////Sysbench///// 

Install:

sudo apt-get install sysbench

run:
sysbench --num-threads=4 --test=cpu --cpu-max-prime=20000 --validate run

............................................................

............................................................

/////Cpuburn-a53/////

Install:

wget https://raw.githubusercontent.com/ssvb/cpuburn-arm/master/cpuburn-a53.S
gcc -o cpuburn-a53 cpuburn-a53.S

run:
while true; do vcgencmd measure_clock arm; vcgencmd measure_temp; sleep 2; done& ./cpuburn-a53

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/////Linpack Bench://///  Be sure to reboot after Install

Install:

sudo apt-get install libmpich-dev
wget http://web.eece.maine.edu/~vweaver/junk/pi3_hpl.tar.gz
tar -xvzf pi3_hpl.tar.gz
chmod +x xhpl

run:
./xhpl

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This is better, not only shows thermals, but also the  freq (so you can see if you are throttling for either heat or voltage):

2 sec readouts:

Scrolling:

while true; do vcgencmd measure_clock arm; vcgencmd measure_temp; sleep 2; done

Non-scrolling:

watch '(vcgencmd measure_temp; vcgencmd measure_clock arm)'

@ Pål Dahle

The module cannot have temps exceed 80C.

However, this range is the maximum for the silicon die; therefore developers should take into account the heat generated when in use and make sure this does not cause the device temperature to exceed 80°C.

At 80C the pi 3 throttles, at 85C all voltage and freq revert back to minimum defaults (for example, at 85C the Pi 3 reverts to 600 MHz). For under voltage, regardless of thermals, Pi 3 thottles/reverts to minimum voltage and freq.

When the Pi throttles/reverts to minimum freq and voltages, performance of the Pi is reduced/degraded as a result.

Here are some stock pi 3 benchmarks (A pi that overheats or is undervolted, will perform beneath the benchmarks, e.g., an undervolting/throttling Pi 3 may only pass at 3 Gflops on the linpack benchmark, indicating a computational performance degradation/loss of approx. 50%):

Sysbench (CPU prime number test) -validated run (passes if completed in 119 seconds or less)

Cpuburn-a53 (thermals and voltage test using neon Instructions) (passes if no throttling occurs, and can maintain thermals at 79C or lower)

Linpack Bench (CPU floating point computing power test, thermals and voltage test using neon Instructions) ( passes if results are 'PASSED'  at 6 GFLOPS (6 billion operations per second) or higher)

https://youtu.be/KuEZV0WsRLg?t=7m20s

Test your Pi/Pi 3, and resolve any voltage/thermal issues as needed:

............................................................

...........................................................

/////Sysbench///// 

Install:

sudo apt-get install sysbench

run:
sysbench --num-threads=4 --test=cpu --cpu-max-prime=20000 --validate run

............................................................

............................................................

/////Cpuburn-a53/////

Install:

wget https://raw.githubusercontent.com/ssvb/cpuburn-arm/master/cpuburn-a53.S
gcc -o cpuburn-a53 cpuburn-a53.S

run:
while true; do vcgencmd measure_clock arm; vcgencmd measure_temp; sleep 2; done& ./cpuburn-a53

..............................................................

..............................................................

/////Linpack Bench://///  Be sure to reboot after Install

Install:

sudo apt-get install libmpich-dev
wget http://web.eece.maine.edu/~vweaver/junk/pi3_hpl.tar.gz
tar -xvzf pi3_hpl.tar.gz
chmod +x xhpl

run:
./xhpl

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