I am always on the look out for tools to analyze system performance. One nifty tool I recently came across is atop, which is an advanced system performance monitor for Linux. When atop is run, it displays overall system utilization in the header, and per-process CPU, memory, network or disk utilization information in the body (you need to patch your kernel to get disk and network utilization). Here is a sample atop session that shows just how awesome this utility is:
I really dig the headers, as well as the network and disk utilization menus. Atop rocks!