Ubuntu Gnome on my laptop boot up using about 310 MB Ram. When running couples of program, the system takes 700 to 900 MB. Then, I close all programs, Ram usage drops but it keeps at 450 ~ 600 MB Ram. Why doesn't it drop to the initial status as booting up. How can I make the system to release Ram automatically when all programs are closed.


Linux uses RAM a little differently to some other operating systems by keeping as much in RAM as it can at all times, my 4GB server often reports 3.5GB of RAM used, but no SWAP in use and runs fast. What I would watch for is when the system starts to use swap, this is normally mounted to your physical disk so is much slower than RAM.

  • After closing all applications, I always use 'sudo swapoff -a && sudo swapon -a' to move everything back to RAM. Jul 30 '13 at 2:33

Actually memory releasing depends on how you are trying to use your Ubuntu. For example If I am using my Ubuntu only for multimedia purpose means I can quickly release the memory after closing the applications.

If I am using my Ubuntu as a server with installed applications like Databases,web serves then They will run in the background even you quit them. Some browsers will keep running in background even after you close them to give the fast opening next time when you click at that.

So what I am trying to say is first find out what are the applications eating up your RAM. you can use command-line tools and as well as GUI tools to do that.

the best are

  • System-monitor(GUI based)
  • top (Command Line)
  • htop (command Line)

In your Unity dash type as system-monitor and you will have an application which can help you to monitor what are the applications eating your memory.

If you want command line tools you can use top and htop.Htop not pre installed but you can install it with

sudo apt-get install htop

System-monitor looks like enter image description here

top looks like

enter image description here

htop looks like enter image description here

hope that helps.

  • These methods are not automatic. Any way I will use them until I know some automatic ways. Thanks. Jul 30 '13 at 2:29
  • we can do that but its not safe. because auto releasing means the only way is simply killing the process but killing a process will cause you get unexpected/wrong behave from that application.
    – rɑːdʒɑ
    Jul 30 '13 at 2:32
  • this is what you need for auto github.com/pshved/timeout
    – rɑːdʒɑ
    Jul 30 '13 at 2:33

Not the answer you're looking for? Browse other questions tagged or ask your own question.