Remember back in May, when Intel claimed that there would be four different versions of Windows 8 for ARM and that none of them would run x86 apps? Microsoft quickly labeled the chipmaker's statements "factually inaccurate," leaving some to think that maybe, just maybe, Windows 8 on ARM would have some sort of compatibility layer. Well, it won't. During Microsoft's latest Financial Analyst Meeting, Windows chief Steven Sinofsky addressed the subject with the following statement:
We've been very clear since the very first CES demos and forward that the ARM product won't run any X86 applications. We've done a bunch of work to enable that -- enable a great experience there, particularly around devices and device drivers. We built a great deal of what we call class drivers, with the ability to run all sorts of printers and peripherals out of the box with the ARM version.
I don't recall Microsoft being particularly clear about the issue, but fair enough. So, what pushed the company not to allow x86 apps to run in the ARM release? Sinofsky explains:
The challenge is very interesting. If we allow the world of X86 application support like that, or based on what we call desktop apps in our start yesterday, then there are real challenges in some of the value proposition for system on a chip, you know, will battery life be as good, for example? Well, those applications aren't written to be really great in the face of limited battery constraints, which is a value proposition of the Metro style apps.
So, we have to be careful that we don't remove the value proposition for those applications. On the other hand, people would say, oh, but you have to let them run because then there's that whole ecosystem. And then if we do let them run, we just brought the perceived negatives of some of the ecosystem. So, people say, great, now it's easy to port viruses and malware and we'll port those.
So, we've taken the approach that we're going to build a bunch of rich capabilities in the operating system that allow devices and peripherals and a broad range of form factors all to run and working with multiple ARM partners on the ARM side, and then Intel and AMD on the system on a chip side, but then focus on the Metro style applications as the opportunity.
Sinofsky did nevertheless point out that Microsoft will allow platform cross-compatibility with Metro apps.
Microsoft's decision probably might not have serious implications as far as ARM-powered Windows 8 tablets are concerned, since those devices won't be geared for desktop productivity, regardless. The decision may nonetheless hurt the appeal of Nvidia's Project Denver CPU, which will be targeted at desktops and servers—systems that would greatly benefit from being able to run legacy x86 apps. (Thanks to The Register for the tip.)