Well yah, the new cores may help or hinder mining. Will have to wait and see. Expected to be 30 percent faster which doesn't always mean faster mining. Still waiting for that 70-80 mh ethereum card.
Dude, to get 2 times of your expected hashrste, i think u better get asic miner for eth like antminer e3, it give u better efficiency at power consuming and cost of rig. Correct me if im wrong.