Noob looking to overclock GPU and/or CPU

[clueless1126]

Hi I upgraded my computer recently and added a powercolor PCD 7870 tahiti GPU and intel i5 3570k. I have never overclocked only seen the 'overdrive' option on CCC. A few questions I have though first, By going into this overdrive and changing anything automatically voids the warranties? And my other question is, if I overclock my CPU do I need a new cooler and heatsink? I'm using the stock cooler? Any help would be awesome, thanks

 

[stormworm]

Any overclock void warranty, but only if they prove you did it. As for the cpu, if you don't raise volt you are ok with stock cooler