Just got my new 2012 iMac set up, I ordered it with 16 gb (2x8) , and then purchased a Corsair Vengeance Kit from Amazon (the one several people have linked in here) it is 1600mhz ram I'm looking right at the box as I type. The model number of the ram confirms it is 1600mhz, CMSX16GX3M2A1600C10 But when I go to "About this Mac" it does show correctly 32GB, but it's running at 1333mhz not 1600mhz. And if I go to Hardware/Memory it shows all 4 sticks running at 1333mhz. Any ideas???