CCC: it's a part of the ATI catalyst driver. the control center.. you have it...
For OC in CCC you use the OVerdrive but it's limited... With the PE bios, you can set how many you will on core, but memory is limited..( stock bios is limited at 700/800 with the PE no limit on core allow you more cause it's at this speed at stock)
The ATi tool new version allow us it for Overclock ( with ATI-tool) or it was bad before this version fo do it...and set the voltage you need when OC.