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Stock Pi 3 B+ in chilly UK Temperature Icon :(

Posted: Mon Mar 19, 2018 5:23 pm
by jewelie
When loading my new Pi 3 B+, should I be getting the temperature icon at any point?

Code: Select all

for ((i=0; i<$(nproc --all); i++)); do nice yes >/dev/null & done
Temperature goes up to 79.5'C, I guess it's throttling at 80'C?

(I'm in the UK, there's snow outside, for reference - it's not hot in here!)

Re: Stock Pi 3 B+ in chilly UK Temperature Icon :(

Posted: Mon Mar 19, 2018 6:12 pm
by wildfire
No temp warning here though my Pi3b+ is lightly loaded. Hardly conclusive but currently 3B+ is running @ 63.4c

Re: Stock Pi 3 B+ in chilly UK Temperature Icon :(

Posted: Mon Mar 19, 2018 7:00 pm
by jamesh
IIRC, we throttle at 80 down to 1200 Mhz, then the same as before at 85. Might be wrong though.

Re: Stock Pi 3 B+ in chilly UK Temperature Icon :(

Posted: Mon Mar 19, 2018 7:02 pm
by jahboater
My 3B+ has settled at 62.3C running your "yes" stress test (in the UK with snow outside).
It does have a small heat sink.

Try this, it uses NEON .....

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

Re: Stock Pi 3 B+ in chilly UK Temperature Icon :(

Posted: Mon Mar 19, 2018 7:07 pm
by jahboater
jamesh wrote:
Mon Mar 19, 2018 7:00 pm
IIRC, we throttle at 80 down to 1200 Mhz, then the same as before at 85. Might be wrong though.
It is 70C

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19:06:44: 68.8'C 1400/1400 MHz 0000000000000000000 1.3688V
19:06:49: 69.8'C 1400/1400 MHz 0000000000000000000 1.3688V
19:06:55: 70.4'C 1400/1200 MHz 0000000000000000000 1.2500V
19:07:00: 70.4'C 1400/1200 MHz 0000000000000000000 1.2500V
later near 80C it slows down further

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19:10:00: 79.5'C 1400/1200 MHz 0100000000000000000 1.2500V
19:10:05: 79.5'C 1400/1200 MHz 0100000000000000000 1.2500V
19:10:11: 80.1'C 1400/1200 MHz 0100000000000000000 1.2500V
19:10:16: 79.5'C 1400/1200 MHz 0100000000000000010 1.2500V
19:10:21: 80.6'C 1400/1195 MHz 0100000000000000010 1.2500V
19:10:27: 79.5'C 1400/1141 MHz 0100000000000000010 1.2500V
19:10:32: 80.6'C 1400/1141 MHz 0100000000000000000 1.2500V
19:10:37: 80.6'C 1400/1200 MHz 0100000000000000010 1.2500V
I must say its quite hard to get it to throttle compared to the old 3B

Re: Stock Pi 3 B+ in chilly UK Temperature Icon :(

Posted: Mon Mar 19, 2018 7:23 pm
by jamesh
jahboater wrote:
Mon Mar 19, 2018 7:07 pm
jamesh wrote:
Mon Mar 19, 2018 7:00 pm
IIRC, we throttle at 80 down to 1200 Mhz, then the same as before at 85. Might be wrong though.
It is 70C

Code: Select all

19:06:44: 68.8'C 1400/1400 MHz 0000000000000000000 1.3688V
19:06:49: 69.8'C 1400/1400 MHz 0000000000000000000 1.3688V
19:06:55: 70.4'C 1400/1200 MHz 0000000000000000000 1.2500V
19:07:00: 70.4'C 1400/1200 MHz 0000000000000000000 1.2500V
later near 80C it slows down further

Code: Select all

19:10:00: 79.5'C 1400/1200 MHz 0100000000000000000 1.2500V
19:10:05: 79.5'C 1400/1200 MHz 0100000000000000000 1.2500V
19:10:11: 80.1'C 1400/1200 MHz 0100000000000000000 1.2500V
19:10:16: 79.5'C 1400/1200 MHz 0100000000000000010 1.2500V
19:10:21: 80.6'C 1400/1195 MHz 0100000000000000010 1.2500V
19:10:27: 79.5'C 1400/1141 MHz 0100000000000000010 1.2500V
19:10:32: 80.6'C 1400/1141 MHz 0100000000000000000 1.2500V
19:10:37: 80.6'C 1400/1200 MHz 0100000000000000010 1.2500V
I must say its quite hard to get it to throttle compared to the old 3B
Thanks for the correction.

I reckon hte thermal management is the real benefit of this model.

Re: Stock Pi 3 B+ in chilly UK Temperature Icon :(

Posted: Mon Mar 19, 2018 7:58 pm
by jewelie
jamesh wrote:
Mon Mar 19, 2018 7:00 pm
IIRC, we throttle at 80 down to 1200 Mhz, then the same as before at 85. Might be wrong though.
Does the temperature icon mean I should be concerned or is it normal under that load?

Re: Stock Pi 3 B+ in chilly UK Temperature Icon :(

Posted: Tue Mar 20, 2018 12:20 am
by wildfire
What load?

The pi will throttle down if overheating, my results were from a PI 3B+ running in a cool room with no case. If yours were in a similar situation then perhaps there is cause for concern but more information is required before we enter the realm of THHGTTG.

Re: Stock Pi 3 B+ in chilly UK Temperature Icon :(

Posted: Tue Mar 20, 2018 10:02 am
by jamesh
wildfire wrote:
Tue Mar 20, 2018 12:20 am
What load?

The pi will throttle down if overheating, my results were from a PI 3B+ running in a cool room with no case. If yours were in a similar situation then perhaps there is cause for concern but more information is required before we enter the realm of THHGTTG.
Jewelie was running a bash stress test that was using all four cores. So you would expect it to get hotter. Whether it would thermally throttle might depend on the chip itself as well an environment.

Re: Stock Pi 3 B+ in chilly UK Temperature Icon :(

Posted: Tue Mar 20, 2018 10:24 am
by HawaiianPi
jewelie wrote:
Mon Mar 19, 2018 7:58 pm
Does the temperature icon mean I should be concerned or is it normal under that load?
Depends on which icon you see. There are 2 temperature icons.

This one means it's getting hot, but not overheated yet, although your Pi will start throttling down performance to try and cool down. If you see this icon occasionally it's probably not something to worry about.

Image

This one means it's hot and throttled down to minimum performance (600MHz and other cores turned off). If you see this one frequently you definitely need some additional cooling.
Image

Re: Stock Pi 3 B+ in chilly UK Temperature Icon :(

Posted: Tue Mar 20, 2018 11:16 am
by jdb
jahboater wrote:
Mon Mar 19, 2018 7:02 pm
My 3B+ has settled at 62.3C running your "yes" stress test (in the UK with snow outside).
It does have a small heat sink.

Try this, it uses NEON .....

Code: Select all

wget https://raw.githubusercontent.com/ssvb/cpuburn-arm/master/cpuburn-a53.S
gcc -o cpuburn-a53 cpuburn-a53.S
./cpuburn-a53
CPUburn is a pathological test that tries to toggle every single register in the CPU as often as possible. You will consume much more power than an equivalent test doing "useful" work. h.265 decode/playback is probably the most strenuous real-world test as it uses significant SDRAM bandwidth, VPU vector code, V3D code, NEON code and all 4 cores at the same time.

Re: Stock Pi 3 B+ in chilly UK Temperature Icon :(

Posted: Tue Mar 20, 2018 2:34 pm
by wildfire
jamesh wrote:
Tue Mar 20, 2018 10:02 am
wildfire wrote:
Tue Mar 20, 2018 12:20 am
What load?

The pi will throttle down if overheating, my results were from a PI 3B+ running in a cool room with no case. If yours were in a similar situation then perhaps there is cause for concern but more information is required before we enter the realm of THHGTTG.
Jewelie was running a bash stress test that was using all four cores. So you would expect it to get hotter. Whether it would thermally throttle might depend on the chip itself as well an environment.
I ran the same test and was a good few degrees lower, environment could also be a factor.

Re: Stock Pi 3 B+ in chilly UK Temperature Icon :(

Posted: Tue Mar 20, 2018 8:03 pm
by jahboater
jdb wrote:
Tue Mar 20, 2018 11:16 am
CPUburn is a pathological test that tries to toggle every single register in the CPU as often as possible. You will consume much more power than an equivalent test doing "useful" work.
Yes exactly.
It is a stress test not a benchmark and the aim is to provide a margin of safety - if the machine can cope, then it will never have the slightest problem with any "useful" workload.

The new 3B+ thermal management does cope easily - very impressive!