How can I see how many processor cores are working?

Question

I have quad-core processor system. I was using Windows before installing Ubuntu. Windows by-default was using 1 core* and I could change that with msconfig. How can I do this in Ubuntu or is it necessary?

Windows was using one core for booting.

Answer 1

Type:

lscpu

in the terminal and press ENTER.

Now you have the info on cores used in your Ubuntu installation.

Answer 2

You can see the usage of your CPU cores using top command.

1. Open a Terminal.
2. Type top. You will see some information about tasks, memory etc.
3. Type 1 to show individual CPU usage. You will see something like:

To start a new process which should execute only in one core, you can use taskset command.

taskset -c 0 executable

To monitor the existing process's CPU affinity, you can use this command:

taskset -cp $(pgrep -f executable)

note that the executable identity you will pass to this command can be './executable' if you started it that way.

Answer 3

As you have not specified your Desktop environment I will assume you are using Using Ubuntu

For a graphical way to check your cpu usage, search your system for an application called System monitor.

The Resources tab will show activity of each core

Whilst the Processes tab will show cpu usage for individual programmes.

Answer 4

htop tool provides graphs for cpu core(s) usage

install htop via terminal:

apt-get install htop

run htop via terminal:

htop

Answer 5

Sensors does this too, but it also tells you the temperature the cores are running at, very cool.

Type sensors in the terminal and it will tell you if you already have it installed, once it's installed you just write sensors