RPi3 CPU temperature

[IriDium]

I've been doing some testing with the RPi3 and Xbian with temperature stress related events.

Under normal conditions, it's fine, but under stupid conditions, it occurs very quickly.

Static the RPi3 runs at around 55 degree, whereas the RPi A & B are 53 degrees. So nothing out of the ordinary.

Stressing the RPi3 for just 60 seconds increases the heat to 81 degrees.

Stressing the RPi3 for just 90 seconds increases the heat to 83 degrees, where the governor kicks in, the CPU freq is reduced and you get a yellow box appear on the screen (just like the rainbow box for low power).

Stressing the RPi3 for just 120 seconds increases the heat to 84 degrees but stays stable. A movie still plays whilst this is going on.

Xbian - still plays when 100% of the CPU is being used.

Adding a fan drops the temperature by about 10 degrees.

Adding a CPU heatsink should reduce it by 5 more degrees. I'm waiting for the sinks to confirm, but I don't expect any variation to other tests on other RPi.

However, it is not hot enough to fry bacon, an egg, nor a hamburger - just in case you were attempting to try!

(Although I'd be interested in any stupid attempts) - normal litigation exceptions apply. (Mainly if you try it,. then you're a dumb ass)

[rikardo1979]

I was reading some article somewhere that this is caused if the wrong kernel is used. Like the kernel build for RPi 2

[deHakkelaar]

Good entertainment
Where's me bacon ...

[IriDium]

Same setup.

Stressing the RPi3 for just 60 seconds increases the heat to 81 degrees.
Stressing the RPi2 for just 60 seconds increases the heat to 60 degrees.

Stressing the RPi3 for just 90 seconds increases the heat to 83 degrees
Stressing the RPi2 for just 90 seconds increases the heat to 60 degrees

Stressing the RPi3 for just 120 seconds increases the heat to 84 degrees
Stressing the RPi2 for just 120 seconds increases the heat to 61 degrees

Stressing the RPi2 for just 240 seconds increases the heat to only 63 degrees

So for frying bacon, the RPi3 is the candidate, visit http://www.rpi3-bacon.com

(No DON'T click on the site, some idiot will create it and try)

[Nachteule]

(11th May, 2016 04:19 AM)IriDium Wrote:  Stressing the RPi3 for just 120 seconds increases the heat to 84 degrees

I suppose at this point CPU will be throttled to 600 MHz. As already told, seems to be design failure and huge heat sink is recommended

[deHakkelaar]

Am not interested in throttling or whatever!
How is the bacon, is it crispy brown ?

[rikardo1979]

(12th May, 2016 05:34 AM)deHakkelaar Wrote:  Am not interested in throttling or whatever!
How is the bacon, is it crispy brown ?

[deHakkelaar]

@rikardo1979 , you scare me with that pic

[IriDium]

I've just found out - by accident I hasten to add - that by placing your finger on the CPU you can drop the temperature by 10 degrees!! Obviously this is not a long term solution!

[Nachteule]

Why not? You have 10 fingers - one for cooling down CPU and the other nine for cooling themselves

[deHakkelaar]

Isn't bacon made from skin ?
A bacon cooled raspi rig
Love the smell.

[IriDium]

Oh my Deity, I've just realised that some idiot might actually try and duplicate the results with other appendages.

Please, please do not try and replicate the result with ANY appendage, especially what you are thinking.

So don't!! It will probably stick and then you will have the embarrassment of going to A/E and trying to explain why you have an RPi stuck to what in old computing technology is a floppy.

XBian will not pay any hospital bills for your stupidity! However we will chuckle for any posts!! (Subject to all legal disclaimers)