The A7 chip in the iPhone 5S is based on an architecture similar to that used for desktop processors

  presenting iPhone 5S and his new face A7, company Apple Lossless Audio CODEC (ALAC), stated that the architecture of its chip is similar to that of chips designed for desktops, and although few believed this at the time, the statement turns out to be true. After a detailed analysis of those from Anandtech, the publication's analysts have come to the conclusion that the new face of those from Apple Lossless Audio CODEC (ALAC), has certain components of the architecture that are similar to the architectures used by Intel for chips dedicated to desktops.

Apple didn't build a Krait/Silvermont competitor, it built something much closer to Intel's big cores. At the launch of the iPhone 5s, Apple referred to the A7 as being "desktop class" - it turns out that wasn't an exaggeration. 

  Chip processor A7 it can process 6 instructions for each load cycle, the Intel Ivy Bridge processors having exactly the same performance, it being double the one recorded in the A6 chip. More than that, the A7 chip has 192 instruction buffers, exactly as much as an Intel Haswell chip, the figure being almost 4 times higher than the one recorded for the A6 chip. Basically, Apple has designed an extremely advanced chip that can evolve extremely much in terms of performance, and all that remains to be done is for Apple to launch the A8 chip.