better dont overclock laptop IMO, your laptop heat up more than desktop because of the poor air flow of laptop ventilating system. just stick to stock voltage la 

then do it at your own risk. use msi-afterburner to unlock voltage and adjust the core clock higher a bit than stock core clock. it will get hotter a lot , say 10C increase with 100mhz increase in core clock frequency. about your fps not increasing, i think you need to increase ram frequency also. hope it helps.

better put a fan cooler below your laptop.

y not?

my crossfire 7970 also using msi afterburner.

you need to unlock it bro, press setting and tick 'unlock voltage'

then it will ask you to restart msi afterburner software.

afterthat you can adjust voltage.

kind reminder, dont go over 1200mV for laptop.

if like this then cannot overclock already.

your gpu locked cannot overclock.

and if you can overclock the performance increase will be less than 5% for laptop gpu