There are several reasons I believe this.
- Over the past few days, both Tom’s Hardware and Anandtech have reported on Intel’s showing them that the Atom is actually more power efficient than ARM. This eliminates ARM’s traditional low power advantage.
- Windows PC OEMs are used to working with x86 when it comes to that OS.
- Windows has a far stronger and longer history on x86 than it does on any other processor architecture.
- Apparently ARM’s upcoming move to 64-bit faces challenges that have already been solved for x86:
Intel and AMD have both pointed out the challenges facing ARM as it moves to 64-bit out-of-order execution, since both companies took years to refine and perfect their own implementations. Memory control is just another one of those areas Intel and AMD dedicate a lot of R&D to optimizing.
The above also explains the following:
- Microsoft’s lack of plans for an ARM version of Windows Server despite various OEMs trotting out ARM server prototypes.
- Windows’ handicapped status on ARM devices relative to its status on x86.
My guess is that Microsoft doesn’t really want to build Windows for ARM. They’re doing it only to appease analysts* and influential pundits*, in addition to ARM being a power efficiency stopgap while Intel got its low power game together. Once that last part happens, I’m expecting Microsoft will either drop or offer only cursory ARM support.
This, however, does not mean that ARM has no future. Unlike Windows, iOS and Android have no legacy x86 heritage. In fact, their heritage is entirely ARM-based for iOS and almost entirely ARM-based in Android’s case. While Android on x86 has been demonstrated, AFAIK no (US market) flagship device features it. Therefore, ARM could still be the long term winner here.
*People who would claim Microsoft has no future if the company doesn’t develop for ARM