When Apple first pulled this stunt of putting in a 64-bit processor into their i5s it forced the industry to follow suite to compete on marketing terms for market share. Sure a 64-bit wide backbone and processor would move data faster than a 32 bit backbone but cell phones can't send or receive enough data fast enough to RAM memory making that extra 32 bit width useful. The data modem and available storage in the phone or SD card in the cell phone is the real speed bottleneck. Every modern day computer including data servers are mostly idle the majority of the time waiting on more data to crunch since they are the fastest part of the hardware design. For a Smartphone the major useful advantage of 64-bit processor is over coming the 32-bit processor address limitations of 4GB of RAM memory. Since the Apple i5s only has 1GB of RAM memory it seems that Apple did this for marketing and future proofing the i5s. Even the Samsung Notes 3 only has 3GB of memory and our Nexus 5 has 2GB.
More and more rumors are pointing to the Nexus 6 having a 64-bit processor.
Leaked Nexus 6 details suggest Google will follow Apple’s lead
G4Games has spotted a new report from Taiwan’s Economic Daily News that claims Google will use a MediaTek 64-bit processor for its upcoming budget Nexus smartphone, often referred to as the “Nexus 6.” The blog says that if the report is accurate, then the next-generation low-cost Nexus will either run a “quad-core MT6732 64-bit chip clocked at 1.5GHz, or the octa-core MT6752 SoC running at a frequency of 2.0GHz,” either of which would be an incredibly powerful processor for a supposed budget device.