Microsoft is readying to introduce Windows 10 with ARM64 structure, a job listing and several other hints reveal. The job listing not only talks about ARM64 across all categories of devices but also talks about its alignment with the Redstone wave. So, it should come in 2016 itself.
Here are relevant sentences from the Job listing.
The silicon ecosystem is always evolving. Windows across all device categories is readying for the introduction of 64 bit computing with the ARM instruction set (ISA). Bringing a new ISA to market involves working both broadly and deeply across Microsoft from devdiv to WDG to Server to Office and others depending on the scope of product target. Many hard system problems need to be discovered and solved to be successful. The role also requires deep engagements in the silicon ecosystem too.
Building the plan for ARM64 aligned with the Redstone wave
Identify the “big rocks” we need to move, solve, make it happen
Build the all up view of where we are, drive the schedule
Work to ensure the necessary hardware is planned for and delivered on time
Drive performance and compatibility goals, define and drive to key metrics
Then there are MSDN documents that reveal Windows 10 Mobile ARM64.
Windows 10 Mobile is currently a 32-bit OS because of the ARM32 structure, it only supports for now. So, while 64-Bit supporting Processors like Snapdragon 808 and 810 are being used in new Lumias, it is not able to take advantage of 64-bit processing. With upcoming ARM64 support, not only we may be able to see more powerful devices and much better Games and Apps support, but may be we can see opening new possibilities like Win32 apps support on Windows 10 Mobile devices.
There have been several mentions about “x86 compat subsystem for Windows on ARM based on x86-to-ARM just-in-time (JIT) emulator”, that may very well enable running of X86 apps on ARM devices. Surface Phone though we hear may run on Intel’s new powerful chip, but if ARM64 support arrives, we can see future Lumia devices based on 64-Bit processors running some x86 apps too.