IF they will play together, YES they will and can run dual channel, and NO they won't automatically downclock to the slowest timing, they will initially boot up to the mobos default and then you will need to set them yourself- both are 4GB sticks and both are 1600, however one stick is CL9 and the other is CL8, best bet will be to try the two at 1600 9-9-9-24, 1.55....and there is no guarantee they will play together, there's never a guarantee using sticks from different packages, even if they are the same exact model.