Samsung likes to tout the high (2.5GHz) clock rate and “eight cores” of its latest Galaxy S5. However, the device still uses either Adreno graphics or ARM Mali graphics (depending on where the model is sold.) Not only do both versions deliver only basic graphics performance, but the split divides the installed base for either chip architecture, making it difficult to impossible for Samsung to get developers to really coax the full performance from either one with some specialized software similar to Apple’s Metal.
The A7 ARM chip introduced with the iPhone 5s, was for having 64 bits. What competitors did not see was the mid/long term Apple’s roadmap for iOS.
Gamers and users needing high graphics capabilities when working with iOS devices are going to see massive improvements in iOS 8.