http://i10.tinypic.com/71zo504.jpg
Chips are Retail, but OEM ...
FPO: 750A, 745A ...
... on default voltage is max OC on Maximus Extreme only 3300MHz for both chips ...
Maximum oc with safe voltage (max 1.45V in BIOS) real 1.38V is for both is about 3800MHz ...
E8400 is not stable at 4GHz at any voltage ... this first 45nm chips are OCers like first Conroes ... nothing special!