Microsoft very quietly confirmed in an unrelated feature article that it plans to release a 64-bit version of Windows 10 Mobile for future smartphones. The current build is only the 32-bit version of the OS.
The mention was buried in an extensive feature posted today on 74-year-old Microsoft Senior Technical Fellow Dave Cutler, who is being honored on April 16 as a Computer History Museum Fellow for his work in the computing industry in general and Microsoft in particular.
In the story, it mentions Culter's work on working to make a 64-bit version of Windows, and the end of the paragraph has the sneak reveal:
In March 2005, he completed one of his "most gratifying pieces of work" at Microsoft when, partnering with AMD, he helped develop the AMD64 architecture (64-bit extensions to the 32-bit x86 architecture) and led the effort to ship the first two x64 64-bit Windows systems (workstation and server). At the time, some questioned why Microsoft developed a 64-bit system; today most computers are 64-bit systems and even our phones will soon have a 64-bit operating system.
The benefits of using a 64-bit OS over a 32-bit one include the ability to have more than 4GB of RAM, better parallel processing, faster bus architecture/app speeds, buffer overflow protection, data execution protection, and Microsoft Patch Guard technology. Those features don't do too much for regular consumers, but they are considered mandatory for enterprise and business environments.
Currently, the Qualcomm Snapdragon 808, 810 and 820 chipsets are64-bit based and fulfill the other half of the 64-bit equation namely the hardware. However, it is not probable that current phones will be able to upgrade from 32-bit to 64-bit for the same reason that you cannot do so on a PC either (at least not directly). Instead, newer hardware down the road will have to feature a 64-bit processor and the 64-bit Windows 10 Mobile OS. All eyes will be on whatever Microsoft releases next year for their alleged Surface Phone.
It's likely that the 64-bit version of Windows 10 Mobile will be released as part of the big Windows 10 Anniversary Update later this year.