When the system gets slower and slower, you need to have dual eyes staring at your machine's CPU and memory and other hardware information to find out the real culprit. This article recommends five system monitoring tools under Ubuntu to keep you Vigilant.
Indicator-SysMonitor
Indicator-SysMonitor is simple but runs well. Once installed and started running, the CPU and memory usage can be displayed on the top panel of the desktop, as shown in:
You can also customize the information to be monitored, display sequence, and refresh frequency:
Download SysMonitor for Ubuntu 11.10.
Download SysMonitor for Ubuntu 10.04.
Conky Set up
Conky is a free, lightweight, and system-monitored X system, that is, any information is displayed on your desktop. It can run on Linux and BSD.
Screenlet
This is a small Desktop component that allows you to intuitively view system resource usage.
Click to install Screenlets
'Top'
Needless to say, the classic commands in Linux, using the console interface, provide comprehensive monitoring information, including the process list and so on.
'System monitor'
This is a built-in monitoring tool, similar to the Job Manager in Windows.
Original article: http://www.oschina.net/news/23135/5-system-monitoring-tools-for-ubuntu