I got the answer from different forum, not Shure if I can say there name but ship and sails logo. The revision numbers determine which actual parts are used in the ram. The number to the left of the decimal point indicates the IC chips, and number on right is the PCB. I got lucky and my memory kit has Samsung 256 IC's which are the fallout from the sorting process used for the 1600C9 modules.
So my memory should work great with the X48 chipset, and have nice head room for overclocking.
They use 9 types of 256 IC's and the Samsung is the top then Micron, Hynix, Promos, Qimonda, Elpida, Psc, Nanya, and Winbond IC's.