Microsoft has announced that they will begin supporting the emulation of existing x86 applications on ARM. This is, in my view, utter BS, FUD and you should keep ignoring the morons.

First of all, if you remember a few years back, 2012, from Steven Sinofsky (at the time head of Windows and of Windows on ARM in particular) :

extrait : "Supporting various forms of emulation runs counter to the goal of delivering a product that takes a modern approach to system reliability and predictability—by definition, existing code has not been optimized for the platform the way WOA (Windows on ARM) has. Virtualized or emulated software will consume system resources, including battery life and CPU, at unacceptable levels. Emulation and virtualization of existing x86/64 software also require the traditional PC environment of mouse and keyboard, which is not a good assumption for WOA PCs.

If we enabled the broad porting of existing code we would fail to deliver on our commitment to longer battery life, predictable performance, and especially a reliable experience over time. The conventions used by today’s Windows apps do not necessarily provide this, whether it is background processes, polling loops, timers, system hooks, startup programs, registry changes, kernel mode code, admin rights, unsigned drivers, add-ins, or a host of other common techniques. By avoiding these constructs, WOA can deliver on a new level of customer satisfaction: your WOA PC will continue to perform well over time as apps are isolated from the system and each other, and you will remain in control of what additional software is running on your behalf, all while letting the capabilities of diverse hardware shine through."

I think this fairly tells you anything you need to know on the subject. And it could be a lot worse in the case of what's announced because WOA was Windows effectively natively running on ARM (both kernel and user) with ARM instructions and tweaked to accomodate the needs of more modern CPU architecture. This along with a new SDK, WinRT, meant to expose features to developers for becoming good citizens (read : do not fuck the battery) on the system.

This has failed miserably in the market, as everyone knows, but at least there was something native, not emulated, to play with. Now Microsoft announces something emulated. It means your compute power is going to spend its time emulating stuff instead of running native code. If it's user mode only (Windows drivers run at the kernel level), it will create so many compatibility problems that everyone will see how shortsighted that was to begin with. And for what reason? Why would someone using so-called legacy X86 apps run them on something else than X86 processors ? If ARM has a more modern architecture which allows to make gains in significant areas, such as battery and so on, there is no free lunch, you have to write code carefully to obtain exactly that. That is the exact opposite of running emulated X86 apps untouched and expecting them to run well.

Emulation is for the past (console games for instance). Modern CPUs have the horse power to meet our needs and we need all that horse power. Plus many if not all ARM devices are portable devices, which means they come along with a plethora of sensors. Desktop computers don't have any. In other words, by doing this, Microsoft is making the same blind move it made with Windows mobile before when they announced a unified API (WinRT) for targeting mobile and desktop devices. That was a non-starter because the devices are so different in just about everything that they need SPECIFIC software to be written for them.



For the record, back in 2012,