mugurdi
Posts: 67
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Raspberry 3 B needs a cooling system?

Sun Oct 22, 2017 4:06 am

Hello,
This Christmas Santa Claus is going to bring me a Raspebrry 3 B ;-). I know that in addition to board I need power supply, microSD, HDMI cable, USB mouse and keyboard, and a box. My question is whether I should also put some cooling system.

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rpdom
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Location: Chelmsford, Essex, UK

Re: Raspberry 3 B needs a cooling system?

Sun Oct 22, 2017 4:44 am

Unless you are going to do something brutal with your Pi or put it in a sealed case, a single small heatsink on the main chip should be sufficient for cooling.

W. H. Heydt
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Location: Vallejo, CA (US)

Re: Raspberry 3 B needs a cooling system?

Sun Oct 22, 2017 5:39 am

I don't use heat sinks or fans on any of my Pi3Bs and they run fine. So...unless you're going to run it really hard or live in an extremely hot climate, no--you don't need a heat sink of fan.

jahboater
Posts: 4674
Joined: Wed Feb 04, 2015 6:38 pm

Re: Raspberry 3 B needs a cooling system?

Sun Oct 22, 2017 7:15 am

The SoC will itself detect when its overheating and reduce the clock speed to keep it cool (throttling). It is pretty robust. If you do a lot of work on the Pi3 and/or its in a poorly ventilated position, a small stick on heat sink may reduce the throttling and give you better performance.
Avoid fans.
I use a 15mm cube heat sink with the fins aligned vertically and the Pi3 mounted on edge in free space. 3M thermal tape. With that arrangement it will survive the worse stress tests.

Remember this command:

Code: Select all

vcgencmd get_throttled
If it returns zero (throttled=0x0), you do not need a heat sink.

If you can run this successfully, you will never have a problem.
The Pi will throttle back, which is expected, but it must not crash:-

Code: Select all

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

piras77
Posts: 148
Joined: Mon Jun 13, 2016 11:39 am

Re: Raspberry 3 B needs a cooling system?

Sun Oct 22, 2017 8:14 am

mugurdi wrote:
Sun Oct 22, 2017 4:06 am
My question is whether I should also put some cooling system.
The SOC checks on its own the temperature and throttles down when it reaches 80°C. So it protects itself against damage. In this sense, it doesn't require cooling.

There must be some significant CPU load for more than a few seconds in order to reach these 80°C. For example, if you plan to play Quake, run heavy builds, join Boinc for parallel computing, etc. None of these are "typical" Raspberry Pi applications.

If you plan to have such high CPU loads that drive the temperature to 80°C in the given environment, and if you want to prevent throttling, then you need to provide some sort of cooling system. A small (about thumbnail size) heat sink will improve the situation. However, in my experience, it won't prevent throttling. You'll also need some sort of fan (which is mostly noisy and thus annoying). There are offers on eBay for enclosure + (noisy) fan for less than 5 bugs. You will also find tons of articles on the internet regarding cooling.

Even though cooling is not required (because of the built-in throttling) it won't be wrong to add a heat sink since it may increase the life-time of the chip (chips tend to live longer on lower temperatures). Whether this is significant and if it matters at all, that's another topic.

jahboater
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Re: Raspberry 3 B needs a cooling system?

Sun Oct 22, 2017 8:24 am

piras77 wrote:
Sun Oct 22, 2017 8:14 am
Even though cooling is not required (because of the built-in throttling) it won't be wrong to add a heat sink since it may increase the life-time of the chip (chips tend to live longer on lower temperatures). Whether this is significant and if it matters at all, that's another topic.
Yes, it can never do any harm to add cooling. However, the expected lifespan of these things is 30-40 years I believe, so I'm not worried about that!

boyoh
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Location: Selby. North Yorkshire .UK

Re: Raspberry 3 B needs a cooling system?

Mon Oct 23, 2017 8:53 am

If you use the Pi within It's normal working power level, you will not need any secondary cooling
When designing your project , If the current load is greater than the Pi working level, use buffer
stages to switch higher current and voltage levels, Use the GPIO's as signal switching of relays
and opto Isolators , using them as voltage and current amplifies from a secondary power supply.
Keep to good safe working practice
BoyOh ( Selby, North Yorkshire.UK)
Some Times Right Some Times Wrong

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RaTTuS
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Re: Raspberry 3 B needs a cooling system?

Mon Oct 23, 2017 9:34 am

if your going to get a case then
https://thepihut.com/products/flirc-ras ... i-3-b-case
or
http://cpc.farnell.com/flirc/101219/cas ... dp/SC13879
or
https://thepihut.com/products/flirc-ras ... i-3-b-case
or
from aliexpress https://www.aliexpress.com/item/New-Ras ... 05786.html [others are available]

[I would also consider using a 1mm heat sink cooling pad .. like
https://www.aliexpress.com/item/100pcs- ... 47490.html [again others are available ]

these will keep it cool running under full power for hours
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counter
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Re: Raspberry 3 B needs a cooling system?

Sat Feb 16, 2019 3:43 pm

I bought a (cheap) case with fan and heat sink on ebay.

The fan would make too much noise (I will not use it), should I add the head sinks anyway?
Attachments
RPIcase01.jpg
RPIcase01.jpg (16.91 KiB) Viewed 3566 times

Idahowalker
Posts: 445
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Re: Raspberry 3 B needs a cooling system?

Sat Feb 16, 2019 4:48 pm

I'd use the heatsinks. For the fan, find the fan location on the underside of the case top. Put a dab of hot glue at each spot the fan will mount to, put the fan on top of the cooled hot glue and then hot glue the fan in place. The layer of hot glue will give a vibration damper. I run my RPi at 70% 24/7, I require a fan.
Without knowing why you are deleting my postings, I will not know how...

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rpdom
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Re: Raspberry 3 B needs a cooling system?

Sat Feb 16, 2019 5:46 pm

I'd use just the larger heatsink on the main chip on a 3B. That's all I use and no matter how hard I push my 3Bs they don't throttle or overheat.

jahboater
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Re: Raspberry 3 B needs a cooling system?

Sat Feb 16, 2019 6:12 pm

+1
That looks like it might be 3M thermal tape which is a good thing.
Make sure the fins are aligned with the airflow.
Best is with the board on edge, in which case the fins should be up/down.

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Imperf3kt
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Re: Raspberry 3 B needs a cooling system?

Sat Feb 16, 2019 9:36 pm

rpdom wrote:
Sat Feb 16, 2019 5:46 pm
I'd use just the larger heatsink on the main chip on a 3B. That's all I use and no matter how hard I push my 3Bs they don't throttle or overheat.
But is it in a case?
I've seen Pi3b temperatures sky-rocket by as much as an additional 20 degrees, just by being enclosed in a case.
55:55:44:44:4C
52:4C:52:42:41

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rpdom
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Re: Raspberry 3 B needs a cooling system?

Sun Feb 17, 2019 6:46 am

Imperf3kt wrote:
Sat Feb 16, 2019 9:36 pm
rpdom wrote:
Sat Feb 16, 2019 5:46 pm
I'd use just the larger heatsink on the main chip on a 3B. That's all I use and no matter how hard I push my 3Bs they don't throttle or overheat.
But is it in a case?
Yes. All of them are in official cases with the lid on.

counter
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Re: Raspberry 3 B needs a cooling system?

Sun Feb 17, 2019 9:30 am

I have definitely no official case, but there is a fan mount on the top. If I don't mount it now, the air flow should be preserved.
RPIcase02.jpg
RPIcase02.jpg (20.55 KiB) Viewed 3442 times
Yes, it looks like an M3 tape with a number 944*
Among the protective film, the tape is black.
RPIcase03.jpg
RPIcase03.jpg (4.93 KiB) Viewed 3429 times
I realized that there are a lot of different kinds of cooling pads and I do not know the differences ...?

For now, I mount the larger heat sink as proposed. Anyway, why are there two small heatsinks with the same size? It is too small for chip on the lower side.

The raspberry runs 24/7 too, with nextcloud, syncthing and some temporary "jobs" :D

Maybe I can put one of the small one's at my old PI1B, should be better than nothing?

Thanks

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Imperf3kt
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Re: Raspberry 3 B needs a cooling system?

Sun Feb 17, 2019 11:42 am

Those heatsink are designed for a Pi3b and fit on the SOC, ram chip and WiFi module.
If they don't fit, maybe you have the pi3b+?

They aren't very good heatsinks, but they're better than nothing, if you require them.
55:55:44:44:4C
52:4C:52:42:41

counter
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Re: Raspberry 3 B needs a cooling system?

Sun Feb 17, 2019 12:21 pm

Imperf3kt wrote:
Sun Feb 17, 2019 11:42 am
If they don't fit, maybe you have the pi3b+?
It is a 3B. I mean, the chip on the back is larger than the smsc chip on the top. The other two heatsinks fits only to the smsc, they have the same size.

However, I attached the heatsink to the SoC. I do not have a thermal measuring device, but the thermal radiation feels much lower than before ... ;)

jahboater
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Re: Raspberry 3 B needs a cooling system?

Sun Feb 17, 2019 5:24 pm

counter wrote:
Sun Feb 17, 2019 12:21 pm
However, I attached the heatsink to the SoC. I do not have a thermal measuring device, but the thermal radiation feels much lower than before ... ;)
You may check the temp with:-

Code: Select all

$ vcgencmd measure_temp
temp=27.7'C

counter
Posts: 11
Joined: Mon May 12, 2014 9:28 pm

Re: Raspberry 3 B needs a cooling system?

Sun Feb 17, 2019 6:32 pm

jahboater wrote:
Sun Feb 17, 2019 5:24 pm
You may check the temp with:-

Code: Select all

$ vcgencmd measure_temp
temp=27.7'C


Thanks. 27°C with a fan?
Now I have no comparision without heatsink.

Idle 41°C
evironment 17°C

Code: Select all

sudo sysbench --num-threads=4 --validate=on --test=cpu --cpu-max-prime=20000 run; vcgencmd measure_temp
sysbench 0.4.12:  multi-threaded system evaluation benchmark

Running the test with following options:
Number of threads: 4
Additional request validation enabled.


Doing CPU performance benchmark

Threads started!
Done.

Maximum prime number checked in CPU test: 20000


Test execution summary:
    total time:                          163.0790s
    total number of events:              10000
    total time taken by event execution: 652.2244
    per-request statistics:
         min:                                 63.26ms
         avg:                                 65.22ms
         max:                                210.76ms
         approx.  95 percentile:              67.79ms

Threads fairness:
    events (avg/stddev):           2500.0000/9.67
    execution time (avg/stddev):   163.0561/0.02

temp=60.7'C


jahboater
Posts: 4674
Joined: Wed Feb 04, 2015 6:38 pm

Re: Raspberry 3 B needs a cooling system?

Sun Feb 17, 2019 6:57 pm

counter wrote:
Sun Feb 17, 2019 6:32 pm
Thanks. 27°C with a fan?
Actually that's a Pi Zero powered digital clock. No heat sink, no fan, nothing.
Its down clocked to 600MHz so that the core voltage is reduced to 1.2V. You don't need much CPU power to run a clock.

Here is a script you might find useful.

Code: Select all

#!/bin/bash
Counter=14
DisplayHeader="Time      Temp    CPU          Health         Vcore"
while true ; do
  let ++Counter
  if [ ${Counter} -eq 15 ]; then
	echo -e "${DisplayHeader}"
	Counter=0
  fi
  Health=$(perl -e "printf \"%19b\n\", $(vcgencmd get_throttled | cut -f2 -d=)")
  Temp=$(vcgencmd measure_temp | cut -f2 -d=)
  Clockspeed=$(vcgencmd measure_clock arm | awk -F"=" '{printf ("%0.0f",$2/1000000); }' )
  CoreVolt=$(vcgencmd measure_volts | cut -f2 -d= | sed 's/000//')
  echo -e "$(date '+%H:%M:%S') ${Temp} $(printf '%4s' ${Clockspeed})MHz $(printf '%020u' ${Health}) ${CoreVolt}"
  sleep 5
done
So you have something to compare against, here is the result running your sysbench command (but you dont need sudo!) on a Pi3B+ with a heat sink but no fan. The Pi3B+ is not overclocked.

Code: Select all

$ sysbench --num-threads=4 --validate=on --test=cpu --cpu-max-prime=20000 run
sysbench 0.4.12:  multi-threaded system evaluation benchmark

Running the test with following options:
Number of threads: 4
Additional request validation enabled.


Doing CPU performance benchmark

Threads started!
Done.

Maximum prime number checked in CPU test: 20000


Test execution summary:
    total time:                          79.8169s
    total number of events:              10000
    total time taken by event execution: 319.2026
    per-request statistics:
         min:                                 31.62ms
         avg:                                 31.92ms
         max:                                101.57ms
         approx.  95 percentile:              32.11ms

Threads fairness:
    events (avg/stddev):           2500.0000/13.58
    execution time (avg/stddev):   79.8006/0.01

Code: Select all

$ ./pistat.sh 
Time      Temp    CPU          Health         Vcore
18:51:39 36.5'C  600MHz 00000000000000000000 1.2V
18:51:44 36.5'C  600MHz 00000000000000000000 1.2V
18:51:50 38.6'C 1400MHz 00000000000000000000 1.3250V
18:51:55 39.2'C 1400MHz 00000000000000000000 1.3250V
18:52:00 39.7'C 1400MHz 00000000000000000000 1.3250V
18:52:05 39.7'C 1400MHz 00000000000000000000 1.3250V
18:52:10 40.8'C 1400MHz 00000000000000000000 1.3250V
18:52:16 40.8'C 1400MHz 00000000000000000000 1.3250V
18:52:21 41.3'C 1400MHz 00000000000000000000 1.3250V
18:52:26 41.3'C 1400MHz 00000000000000000000 1.3250V
18:52:31 42.4'C 1400MHz 00000000000000000000 1.3250V
18:52:36 41.9'C 1400MHz 00000000000000000000 1.3250V
18:52:41 42.9'C 1400MHz 00000000000000000000 1.3250V
18:52:47 41.9'C 1400MHz 00000000000000000000 1.3250V
18:52:52 42.9'C 1400MHz 00000000000000000000 1.3250V
Time      Temp    CPU          Health         Vcore
18:52:57 42.9'C 1400MHz 00000000000000000000 1.3250V
18:53:02 43.5'C 1400MHz 00000000000000000000 1.3250V
18:53:07 42.4'C  600MHz 00000000000000000000 1.2V
18:53:12 41.3'C  600MHz 00000000000000000000 1.2V
18:53:17 40.8'C  600MHz 00000000000000000000 1.2V
About 20C ambient.
The Pi3B+ is outside of a case and mounted on edge.

counter
Posts: 11
Joined: Mon May 12, 2014 9:28 pm

Re: Raspberry 3 B needs a cooling system?

Sun Feb 17, 2019 7:46 pm

jahboater wrote:
Sun Feb 17, 2019 6:57 pm
The Pi3B+ is outside of a case and mounted on edge.
Thanks, it seems, that your heatsink is much better by handling temperatures (or the 3B+). What kind of heatsink is mounted?

Code: Select all

$ ./pistat.sh
Time      Temp    CPU          Health         Vcore
20:28:11 42.9'C  600MHz 01010000000000000000 1.2V
20:28:16 42.9'C  600MHz 01010000000000000000 1.2V
20:28:21 42.9'C  600MHz 01010000000000000000 1.2V
20:28:27 46.2'C  700MHz 01010000000000000000 1.2750V
20:28:32 48.3'C  700MHz 01010000000000000000 1.2750V
20:28:37 49.4'C  700MHz 01010000000000000000 1.2750V
20:28:43 50.5'C  700MHz 01010000000000000000 1.2750V
20:28:48 50.5'C  700MHz 01010000000000000000 1.2750V
20:28:53 51.5'C  700MHz 01010000000000000000 1.2750V
20:28:59 52.6'C  700MHz 01010000000000000000 1.2750V
20:29:04 52.1'C  700MHz 01010000000000000000 1.2750V
20:29:09 52.6'C  700MHz 01010000000000000000 1.2750V
20:29:15 53.2'C  700MHz 01010000000000000000 1.2750V
20:29:20 53.7'C  700MHz 01010000000000000000 1.2750V
20:29:25 53.7'C  700MHz 01010000000000000000 1.2750V
Time      Temp    CPU          Health         Vcore
20:29:31 54.8'C  700MHz 01010000000000000000 1.2750V
20:29:36 55.3'C  700MHz 01010000000000000000 1.2750V
20:29:41 54.8'C  700MHz 01010000000000000000 1.2750V
20:29:47 55.3'C  700MHz 01010000000000000000 1.2750V
20:29:52 55.8'C  700MHz 01010000000000000000 1.2750V
20:29:57 56.4'C  700MHz 01010000000000000000 1.2750V
20:30:03 56.4'C  700MHz 01010000000000000000 1.2750V
20:30:08 56.4'C  700MHz 01010000000000000000 1.2750V
20:30:13 56.4'C  700MHz 01010000000000000000 1.2750V
20:30:19 56.9'C  700MHz 01010000000000000000 1.2750V
20:30:24 56.9'C  700MHz 01010000000000000000 1.2750V
20:30:29 56.9'C  700MHz 01010000000000000000 1.2750V
20:30:35 57.5'C  700MHz 01010000000000000000 1.2750V
20:30:40 58.0'C  700MHz 01010000000000000000 1.2750V
20:30:45 58.0'C  700MHz 01010000000000000000 1.2750V
Time      Temp    CPU          Health         Vcore
20:30:51 58.0'C  700MHz 01010000000000000000 1.2750V
20:30:56 58.0'C  700MHz 01010000000000000000 1.2750V
20:31:01 58.0'C  700MHz 01010000000000000000 1.2750V
20:31:06 55.8'C  600MHz 01010000000000000000 1.2V
20:31:11 53.2'C  600MHz 01010000000000000000 1.2V
20:31:16 52.6'C  600MHz 01010000000000000000 1.2V
20:31:22 51.5'C  600MHz 01010000000000000000 1.2V
20:31:27 51.0'C  600MHz 01010000000000000000 1.2V
20:31:32 49.9'C  600MHz 01010000000000000000 1.2V
20:31:37 49.4'C  600MHz 01010000000000000000 1.2V
20:31:42 49.4'C  600MHz 01010000000000000000 1.2V
20:31:47 49.4'C  600MHz 01010000000000000000 1.2V
20:31:52 48.3'C  600MHz 01010000000000000000 1.2V
20:31:57 48.3'C  600MHz 01010000000000000000 1.2V
20:32:02 47.8'C  600MHz 01010000000000000000 1.2V
Time      Temp    CPU          Health         Vcore
20:32:07 47.2'C  600MHz 01010000000000000000 1.2V
20:32:12 47.8'C  600MHz 01010000000000000000 1.2V
20:32:17 46.7'C  600MHz 01010000000000000000 1.2V
20:32:23 46.2'C  600MHz 01010000000000000000 1.2V
20:32:28 46.2'C  600MHz 01010000000000000000 1.2V
20:32:33 46.2'C  600MHz 01010000000000000000 1.2V
20:32:38 46.2'C  600MHz 01010000000000000000 1.2V
20:32:43 46.2'C  600MHz 01010000000000000000 1.2V
20:32:48 46.2'C  600MHz 01010000000000000000 1.2V
20:32:53 46.2'C  600MHz 01010000000000000000 1.2V
20:32:58 45.6'C  600MHz 01010000000000000000 1.2V

jahboater
Posts: 4674
Joined: Wed Feb 04, 2015 6:38 pm

Re: Raspberry 3 B needs a cooling system?

Sun Feb 17, 2019 7:50 pm

Its a Kintaro heat sink.
https://www.amazon.co.uk/Kintaro-Alumin ... o+heatsink
Very effective. Its bolted on so uses decent thermal paste rather than sticky tape.
It also cools the USB/ethernet chip that can get hot now its GiGe.

And yes, the Pi3B+ is much much better at thermal management than the old 3B.

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