If you installed AMD/ATI, you will have a chance to work with aticonfig
command which is very flexible and provides bunch of options for you. Here I introduce two options which I use very frequently. If you want to get temperature of your graphic card, type the following command in your terminal.
$ sudo aticonfig --od-gettemperature
You also can get the fan speed with the below command,
$ sudo aticonfig --pplib-cmd "get fanspeed 0"
If you want to get more information about this command, refer to man page.