Time (benchmark) your commands
Perhaps unexpected, the time command, doesn’t actually give you the system time (use date for that). What it is does is “time” how long something takes to run (so a different use of the word time).
So for example, let’s say you are doing a mysql import, you can prepend it with time to find how long it took to run:
$ time mysql -u user -p db < import_file.sql
A quick and useful benchmark, even if it only lets you know how long you have to go make a coffee :)