System Load Indicator is a quick way to keep monitoring your machine CPU, memory, swap, network download/upload speeds, hard disk read/write traffic, and overall load in your system.
If you have been using Conky system monitory applications before, you will find some similarity between them, for indicating your CPU, memory and hard disk usages,… etc. System load indicator become handy and easily to see all the time without minimizing your currently running applications in your session. also you can open your default system monitor application through system load indicator menu.
How to Install System Load Indicator In Ubuntu 11.04 Natty Narwhal
sudo add-apt-repository ppa:indicator-multiload/stable-daily
sudo apt-get update
sudo apt-get install indicator-multiload
Then click Alt+F2 then type
It will show up in your Unity panel. Click the system load indicator to display your real time statics, also you can select preferences to customize your graphs colors and if you like to auto start system load indicator with your system.