Table of contents

RoadTest: RoadTest Review a Raspberry Pi 3 Model B !

Author: gpolder

Creation date: 18 May 2016

Evaluation Type: Independent Products

Did you receive all parts the manufacturer stated would be included in the package?: True

What other parts do you consider comparable to this product?: The Pi rules!

What were the biggest problems encountered?: an old NOOBS card from a Pi B (not the B+) didn't work.

Detailed Review:

Introduction

The topic I promised  to discuss in my roadtest application is heat dissipation related to use of the Pi 3 for home automation.

There were some rumors on the net that the processor temperature can be as high as 100 degrees celsius at 100% CPU.

Current setup

Currently I'm running an home automation system using a Pi 2 model B, which controls the lights in the house, measures temperature and also a connected camera detects intruders.

For monitoring the system itself I have a temperature sensor in the cabinet and also monitor the CPU temperature.

Here is a picture of the webpage which shows me the graph of the current month:

You will see the temperature of the power supply (green), the case itself (purple) and the CPU (top one).

You can see that it follows the ambient temperature, including day/night rhythm.

What I tested

So I was curious about the heat transmission is om the Pi 3. I saw some tests on the internet who states that the CPU under 100% load can go higher than 100 degrees celsius. (http://www.gizmodo.com.au/2016/03/the-raspberry-pi-3s-quad-core-cpu-can-hit-a-toasty-100c-under-load/ )

For home automation I don't need a lot of computing performance, while power dissipation is much more important.

First I did a CPU test using sys bench, on three types of the Raspberry Pi, my current home automation system (Pi 2), a Pi B+, and the Pi 3 from the roadtest.

Here is a picture of the Pi B+ (left) and Pi 3, laying on my desk.

sys bench can be installed using: sudo apt-get install sysbench

For monitoring the temperature I used RPiTemperature from: http://www.roylongbottom.org.uk/Raspberry_Pi_Stress_Tests.zip

wget http://www.roylongbottom.org.uk/Raspberry_Pi_Stress_Tests.zip
unzip Raspberry_Pi_Stress_Tests.zip 
cd Raspberry_Pi_Stress_Tests/
chmod +x RPiTemperature 
./RPiTemperature passes 700, seconds 2 &

Here is the result of sys bench on all three boards. Of course I know that --num-threads=4 doesn't make much sense on the Pi 2 and Pi B+, but I don't expect it influences the results a lot.

Pi B+ cpu sys bench:

pi@zolderpi ~/stres_test $ sysbench --num-threads=4 --test=cpu --cpu-max-prime=20000 --validate 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:                          1329.8390s
    total number of events:              10000
    total time taken by event execution: 5318.6407
    per-request statistics:
         min:                                351.47ms
         avg:                                531.86ms
         max:                               1132.11ms
         approx.  95 percentile:             551.17ms

Threads fairness:
    events (avg/stddev):           2500.0000/0.00
    execution time (avg/stddev):   1329.6602/0.13

Pi 2 B cpu sysbench:

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:                          293.8832s
    total number of events:              10000
    total time taken by event execution: 1175.3010
    per-request statistics:
         min:                                117.00ms
         avg:                                117.53ms
         max:                                160.74ms
         approx.  95 percentile:             118.04ms

Threads fairness:
    events (avg/stddev):           2500.0000/11.02
    execution time (avg/stddev):   293.8253/0.04

Pi 3 B cpu sysbench:

pi@pi1pi3test ~/stress_tests/Raspberry_Pi_Stress_Tests $ sysbench --num-threads=4 --test=cpu --cpu-max-prime=20000 --validate 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:                          246.9762s
    total number of events:              10000
    total time taken by event execution: 987.6050
    per-request statistics:
         min:                                 96.08ms
         avg:                                 98.76ms
         max:                                214.33ms
         approx.  95 percentile:              97.46ms

Threads fairness:
    events (avg/stddev):           2500.0000/54.59
    execution time (avg/stddev):   246.9012/0.02

During the tests I logged the temperature with a 2 seconds interval and plotted the results using plot.ly. Below you will see the results.

  

Final remarks

My conclusion is that I continue to use the Pi 2 for my home automation, and use the Pi 3 for more demanding tasks, such as software defined radio.

During my experiments A Comprehensive Raspberry Pi 3 Benchmark was added to Element14 by cstanton

I hope my findings above will contribute a little bit to that.

Do not hesitate to contact me when you have some questions.