Power Draw

[chip ling]

I got my Pinebook Pro this week. After I fixed my ANSI keyboard mapping and then I saw this post.

So I decided to do a power consumption test run on my Pinebook Pro.

Objective: very light usage + headless test run
Run time: 10 hours
Result: run for 10 hours and still have 11% battery left

Here is what I did: (I use the "on demand" power scheme)

1. turn off the machine and fully charge the Pinebook Pro overnight before the testing start.

2. Power on the Pinebook Pro, start 2 apps: Power Statistics and System Monitor and let it run. Also start a terminal running the top command.

3. I let the Pinebook Pro idle with the above 3 apps running. After a while the screen switch off.

4. I went to work and logon to my Pinebook Pro via ssh terminal.

5. I continuously check the power level and cpu temperature. (temperation is average at 33.33 degrees C)

6. The battery power level drop 1% after every 7 minutes.

7. After three hours, I wrote another assembly program as below.

Code:

       .global _start
_start:
       mov     r1,#0x25        @ r1 = 0x25
       mov     r2,#0x34        @ r2 = 0x34
       add     r3,r2,r1        @ r3 = r2 + r1
here:   b       here            @ loop forever here

This is an endless looping program, the objective is to use up one cpu core and see how it impact the battery and temperature.

I compiled this program and run it on the background.

I run the "top" command on my terminal and see the program used up 100% cpu. So one core has been fully occupied.

The cpu temperature rised from 33.33 to 46.1 degrees.

I let the program ran for 45 minutes before I killed the process. During the program running time, the power consumption increase to every 1% power drop, took 5 minutes. The temperature also dropped slowly.

I run the "top" command on the ssh terminal until the rest of the test.

Then I let the Pinebook Pro run as headless Linux machine.

After 10 hours, I still have 11% battery left. I stopped the test.