hi you all, i was upgrading my imac 2012 with a ssd owc aura, since i need to open the case and take out the motherboard, i'd like to upgrade my cpu too, i've now the 2.9ghz i5, lga 1150, so can i upgrade to a i7 4.0ghz? what should be the highest speed cpu i can upgrade on it please help. thank you.