Since the 4 Samsung Galaxy S was launched in the world market for some unique versions is the Asian market. Samsung Duos launched four models of Samsung Galaxy S (I9502) including some notable differences from the standard that many people can receive. First, the Galaxy S Duos has 4 slots for two SIM card. Second, the version of the flagship Samsung duos with 5 octa Exynos chip will be equipped with 1.6 GHz clocked each heart. All other functions of the device are the same as the other models Galaxy S 4
Another model for the Chinese market, the I9506, designed runs a Snapdragon processor 600 and is limited to the 3G TD-SCDMA connectivity.
source: Samsung China