I noticed there's a new version of Gnome system monitor while my version is 3.18.2. I tried to remove and reinstall it but I still have the same version. Opening Software Updater doesn't recommend me an update.
On my Xenial system
gnome-system-monitor is fairly straightforward to build from source. First allow access to source code:
Dash > Software & Updates > Ubuntu Software > Source Code
Then allow the system to reload the repositories. Pick up the build dependencies for
gnome-system-monitor by running the following from within a Terminal window:
sudo apt-get build-dep gnome-system-monitor
Then download, compile and install
gnome-system-monitor with the following single command which can be copied and then pasted into a Terminal window:
sudo apt-get install build-essential checkinstall && \ mkdir -v $HOME/Desktop/gnome-system-monitor_build && \ cd $HOME/Desktop/gnome-system-monitor_build && \ wget https://download.gnome.org/sources/gnome-system-monitor/3.20/gnome-system-monitor-3.20.1.tar.xz && \ tar xvf gnome-system-monitor-3.20.1.tar.xz && cd gnome-system-monitor-3.20.1 && \ ./configure && make && \ sudo checkinstall --pakdir "$HOME/Desktop/gnome-system-monitor_build" \ --backup=no --deldoc=yes --pkgname gnome-system-monitor --pkgversion 3.20.1 \ --fstrans=no --deldesc=yes --delspec=yes --default
Log out and then back in (or simply open Dash, close it and then reopen it) and you should then see the following, (a screenshot taken from my own installation on Xenial Xerus):
Runs nicely on my system and when a new version is released this method can easily be tweaked to install the very latest version :)
Ubuntu uses tested version of Gnome thats older. If you wish to use latest, install Ubuntu Gnome and then add Gnome PPA but get ready for some issues. I use Arch with Gnome 3.2, so far its been OK but issues crop up from time to time.
Have you tried
sudo apt-get install, followed by its package name? In this case it's
sudo apt-get install gnome-system-monitor.
Should you have no idea what this is: Open Terminal, copy and paste the following command, press Enter, input your password (which you might not see the asterisks as you type -- just keep typing), press Enter, and answer any prompts that may be on screen.
For Ubuntu, the latest version of System Monitor is 3.20.1-1.