Apple's iPhone 5S, arriving within days, begs the question of what can you do with 64-bit memory addressability in a smartphone. I suspect the answer is, "Not much."
When ARM announced its V8 architecture for a 64-bit core the handwriting was on the wall. This was all about servers where the software stack is pretty much entirely based on 64-bit address spaces.
ARM and as many as a dozen of its SoC partners are gearing up an interesting initiative here that will bear its first fruits in 2014. So far, Intel still has the lead in low-power servers.
But mobile? There is no 64-bit software here yet. We are not approaching the 4 Gbyte main memory limit of today's 32-bit systems.
Analysts I talked to, such as Kevin Krewell of The Linley Group and David Kanter of Real World Tech, said they don't expect to see any user value in a 64-bit A7 chip in the iPhone 5S. This is all about plowing the field for a future ecosystem. However Kanter noted there could be some performance advantages for simplifying virtual memory operations in devices at or above a Gbyte of main memory.
Far be it from me to be the Luddite who says smartphones will never need more than 4 GBytes of memory. A better question is: What could they do with that much memory?
Apple took a stab at that question when it also opened the door to a sensor fusion API riding on top of its new M7 sensor controller. Samsung had a jump on Intel with all the sensor bells and whistles in its latest Galaxy S phones. Now, Apple is calling the iPhone faithful to think different about what it could deliver.
I stopped wearing watches years ago and have no interest in the new health and fitness devices popping up. But I don't doubt something interesting could emerge there someday.
I suspect no one really knows what to do -- that's compelling -- with a smartphone that sports 64-bit memory spaces and biometrics, including Apple. The Cupertino company is just opening a door and seeing what passes through it. Like the iPhone maker, I'm curious to hear your thoughts, too.