I'd like to get a setup of XQt with a window manager that will tax enable the apps to run the fastest.

How can I measure how fast the system is when comparing for instance blackbox and fluxbox and so?

Also, can I somehow measure if for instance firefox runs faster under XQt or XQt-2, is there some benchmark tool I can use for this, other than very crudely counting how many seconds firefox takes to start under the two different configurations?