Everyone knew Samsung was offering different variants of the Galaxy S 4 based on region, but according to an IHS iSupply teardown, that difference goes a little deeper than just the CPU.
According to the teardown, the US variant of the phone uses a separate Fujitsu image processor to handle functions such as the eye tracking and scrolling features that Samsung has heavily promoted. The reason behind this is that the Snapdragon S600 apparently couldn’t handle the processor intensive tasks alone, so Samsung improvised. The Exynos version of the phone doesn’t have the extra processor. Overall, it’s not really a huge deal, as most users probably wouldn’t be able to tell the difference anyway. And, honestly, that’s a pretty smart move by Samsung to make both versions of the device perform roughly the same.
The teardown also revealed that the US version uses different hardware for WiFi, Bluetooth, GPS, etc., although I’m sure that had more to do with cost and availability than performance.