Slashdot Mirror
Microsoft and Qualcomm Collaborate To Bring Windows 10, x86 Emulation To Snapdragon Processors (anandtech.com)
An anonymous reader quotes a report from AnandTech: Today at Microsoft's WinHEC event in Shenzhen, China, the company announced that it's working with Qualcomm to bring the full Windows 10 experience to future devices powered by Snapdragon processors. These new Snapdragon-powered devices should support all things Microsoft, including Microsoft Office, Windows Hello, Windows Pen, and the Edge browser, alongside third-party Universal Windows Platform (UWP) apps and, most interestingly, x86 (32-bit) Win32 apps. They should even be able to play Crysis 2. This announcement fits nicely with Microsoft's "Windows Everywhere" doctrine and should come as no surprise. It's not even the first time we've seen Windows running on ARM processors. Microsoft's failed Windows RT operating system was a modified version of Windows 8 that targeted the ARMv7-A 32-bit architecture. It grew from Microsoft's MinWin effort to make Windows more modular by reorganizing the operating system and cleaning up API dependencies. The major change with today's announcement over Windows RT and UWP is that x86 apps will be able to run on Qualcomm's ARM-based SoCs, along with support for all of the peripherals that are already supported with Windows 10. This alone is a huge change from Windows RT, which would only work with a small subset of peripherals. Microsoft is also focusing on having these devices always connected through cellular, which is something that is not available for many PCs at the moment. Support will be available for eSIM to avoid having to find room in a cramped design to accommodate a physical SIM, and Microsoft is going so far as to call these "cellular PCs" meaning they are expecting broad support for this class of computer, rather than the handful available now with cellular connectivity. The ability to run x86 Win32 apps on ARM will come through emulation, and to demonstrate the performance Microsoft has released a video of an ARM PC running Photoshop.
The takeaway is that simply emulating the x86 instruction set results in about a 100x slowdown for an equivalent clock rate.
Emulation definitely results in slowdowns, but it's generally much less than 100x. In particular since any emulator that focuses even slightly on performance uses dynamic compilation: it translates the code once from x86 to the host architecture and from then on runs this translation. The translated version will probably be less efficient than the original code, but by no means 100x slower. 2x to 5x seems more realistic on average, although there are certainly outliers (e.g. code that intensively mucks with system registers or that triggers context switches will be slower, while some straightforward calculation loops may actually become just as fast as or even faster than the original code depending on the target architecture's nature).
Donate free food here
So far in the micro server and embedded space, ARM has been particularly disappointing to me. I have a drawer full of ARM devices I've accumulated over the years. SheevaPlugs, GuruPlugs, RouterStation, etc. All are potentially useful devices, but ARM is hobbled by proprietary boot systems and differing device trees and proprietary supporting hardware. These devices rely on customized linux distributions, and they are often fairly hard to update to new kernels and new flash file systems. Some of these devices have good CPU performance specs, but in practice I've never had them outperform an intel-based server, even a small low-powered one like the atom.
And now in embedded space we have a plethora of Arm-based devices based on lots of different SoCs from companies all over the world. All with their own forks of Linux. We've got Raspbery Pis, Orange PIs, Pine64s, etc. All very interesting and probably useful. But a nightmare to do anything with in a sustainable way.
The Pi (and some of these devices) at least is easy to update since everything comes off of the sd card, with no kernel flashing required. And some of them like the Pi have a fair amount of hacker inertia behind them, so they are capable of doing cool things (maybe not as server replacements though).
With x86-based embedded systems and small servers, at least I can run more standard, off-the-shelf distros on them. I'd far rather deal with a conventional linux server than a sheevaplug, even if the sheevaplug is a nice tiny thing with lots of potential.
In fact my current home office router is a small, low-power Intel-based computer running bog standard, minimal install of CentOS 7. Wifi is hung off of that using a consumer-grade access point running in bridge mode.
If arm devices had a standard boot process like ufi or even the bios, and could boot off of a variety of devices in a standardized way, including ssds, hard drives, usb sticks, and internal flash storage, and could run stock distributions downloaded from distribution web sites, without custom kernels, then I'd say for sure x86's days are numbered. Arm is good at remaining fragmented though.