The eight-core Samsung Galaxy S4 variant will only be made available in Africa, Asia, and in certain countries in Europe, according to a report. The quad-core Snapdragon 600 variant will, however, be available worldwide. Apart from the processor, the eight-core GT-I9500 will feature a PowerVR SGX 544 graphics processor, and will be available on 3G HSPA+. The quad-core model, the GT-I9505, on the other hand, will offer a Adreno 320 graphics processor and 4G LTE connectivity.
Based on the specs, it would seem strange that Samsung would choose not to offer the eight-core variant in the more established markets such as in the US, however there is some speculation as to Samsung's reasoning. Analyst Gus Richard suggests that Samsung may have had some power issues with its new eight-core Exynos 5 Octa chip. This would mean that the device would likely need to be delayed for release until the issue is resolved.