100% CPU all the time

[johnmiller]

I have a Raspberry Pi 2 Model B. It is running at 100% pretty much constantly.

Here is what I am running:
* Raspbian Jessie with Pixel (updated)
* FlightRadar24 Feed - http://feed.flightradar24.com/ - Sends flight data to server using USB antenna.
* VNC Server - https://www.realvnc.com/raspberrypi/ - Included with Jessie, allows viewing of Pi on other devices.
* Cayenne - https://mydevices.com/cayenne/features/ - Allows Pi status to be viewed on Android app.

I set the resolution of my Pi down to Default, but that didn't help.

My questions:
* Is it normal for my Pi to be running at 100%?
* Is it okay for the Pi to be running at 100% all the time?
* Is there any way I can reduce the load on the processor?

Thank you for your help!

[kusti8]

It is OK for it to be running 100%. You can check usage by opening a terminal and typing in:
top
And looking at the processes and how much CPU they use.

[johnmiller]

Thank you!

[HawaiianPi]

I have a Raspberry Pi 2 Model B. It is running at 100% pretty much constantly.

* Is there any way I can reduce the load on the processor?

Which version of the Pi2 do you have?

The newer version 1.2 uses the same BCM2837 SoC as the Pi3, and it's a more efficient chip than the older BCM2836 SoC, so it could run at a reduced load even at the same 900MHz clock speed. You could also overclock it to 1.2GHz (the default speed of the Pi3), but I would recommend a fan and/or heatsink at that speed with high software loads.

Of course the other option would be to get a Pi3. The difference between the Pi2v1.2 and Pi3 is the higher default clock speed (Pi2v1.2=900MHz, Pi3=1.2GHz) and the Pi3 includes built-in WiFi & Bluetooth. If you don't need the built-in wireless features then a Pi2v1.2 clocked at 1.2GHz should give the same performance as a Pi3.

[ktb]

Extra tip... When top is running press the 1 key on your keyboard to see the usage of each core.

[johnmiller]

Thank you for the replies! I appreciate them.

A Pi 3 would help a little bit, but I am guessing I would max that baby out too in no time!

Here is one thought I had: Just use a PC or design a Linux-dedicated computer. I have built computers before. Also, I have Raspbian Jessie with Pixel running through a USB boot on a small ASUS laptop I have, and the CPU is at about 13% (a little bit lower than on my Pi!).

The issue, though: I want to prototype. But, I have not come across a way to interface a breadboard with a PC through USB or some other interface. Is there some way to do that?

Thank you again!

[mfa298]

As others have suggested top (or htop) will let you see all the things that are running on the Pi and see what's generating the load.

Initially I would suspect Cayenne but that's based on no real evidence. Running something to upload to FR24 shouldn't stress the Pi that much (I ran some tools for RF24 a few years ago on a Pi1 with no issues).

[jamesh]

This is not down to the Pi itself, something is simply running a loop without reliquishing processor time during the loop when it doesn't need it (i.e. with a sleep or similar)

One of the apps you are running is slightly badly behaved/badly coded.

[johnmiller]

Cayenne was the culprit. I killed it.

If any of you out there want to know how to uninstall it, here you go:

Code: Select all

sudo systemctl disable myDevices
rm -rf /etc/systemd/system/myDevices.service
rm -rf /etc/init.d/myDevices
rm -rf /usr/bin/myDevices
rm -rf /etc/myDevices/