Are 64-bit CPUs Gimmicks? Short Answer: No, but technically yes, though not really.

When Apple announced its 64-bit A7 chip last year, competitor chipmakers were left, as a Qualcomm employee put it, “slack-jawed and stunned.” Soon after, Qualcomm released a statement claiming that 64-bit mobile processors were gimmicks that didn’t really help with performance. The company then hastily corrected this declaration, saying its previous remarks weren’t entirely accurate.

Internet forums exploded with debates on this issue with some even claiming that Apple had lied about its new silicon. Within weeks, however, A7 benchmarks proved that the enormous performance gains were real. But was this improvement really due to the 64-bit upgrade?

Technically, “64-bit” refers to a central processing unit’s ability to handle 64-bit integer operations which, in turn, allows it to use larger amounts of RAM (greater than 4 gigabytes). Since the iPhone has only one gigabyte of RAM, it cannot take advantage of this.

What was mostly responsible for the A7’s impressive performance was something that came with the 64-bit capability: a newer, streamlined, and far more efficient ARMv8 instruction set. ARMv8 was a major update to ARMv7 that refined existing existing instructions, eliminated outdated ones, added more modern designs, and implemented support for 64-bit processors.

Thus, Apple was both truthful and misleading about the significance of 64-bit and by extension ARMv8.  However, Apple and now Qualcomm (with its Snapdragon 810 processor) and Nvidia (with its “Project Denver” Tegra K1 processor) continue to praise the power of 64-bit without mentioning ARMv8 because — let’s face it — 64-bit sounds cooler and is less confusing to the average consumer.

The introductions of 64-bit architecture and ARMv8 have introduced newer, exciting capabilities to mobile processing that will make developers and consumers alike re-imagine what is possible when working or playing on the go.

Written by Raymond Cao’17