Getting the most out of your Linux desktop can be easy if you have a great new machine loaded with oodles of RAM. But, if you have older hardware, perhaps limited in memory, and you still want to heavily use the system with as much responsivenes as possible, then you are obviously interested in tuning the performance. Even with 2GB of RAM, running on a relatively good piece of hardware, you may want to investigate ways to get more performance out of your system so that it's as fast as you are. :-)
One good article on the subject is at http://www.ibm.com/developerworks/linux/library/l-linux-memory.html They talk about using the "free" command to look at your memory. Although you can add a -s switch to redo the command every so many seconds, this will just run output scrolling through your console, so the better option would be to use free in tandem with watch which has the added benefit of being capable of highlighting the differences for you.
# see how memory is being used (in Megabytes)
# hit "Ctrl C" to cancel
watch -n 1 --differences free -m
Amazon Web Services (AWS) points to this article on host tuning as reference (; which is very lame in my opinion. Amazon should have a whole wiki dedicated to host tuning!)
Tools
What tools should be used to measure performance and tune system variables?
https://k6.io/ K6 is a performance testing tool, but their install instructions don't work for RedHat, so we'll skip it for now.
siege (and here) is an old standby, which installs effortlessly, so we'll give that a try
See Also
To help optimize your web server, see the PHP Accelerator article