You know that Samsung has launched Galaxy S IV in 2 variant, one had Exynos 5 Octa 5 processor which is has 8 cores and this processor is being used in global version of Galaxy S IV aka GT-I9500.
On the other hand US version of S IV aka GT-I9505 comes with Qualcomm’s Snapdragon 600 quad-core processor.
Exynos 5 Octa 5 is Samsung’s self made and is based on ARM big.LITTLE architecture, Snapdragon processor is made by Qualcomm and it is well designed for LTE, so Samsung is going to use Qualcomm processor in LTE market and in other they will use Exynos 5 Octa 5.