Backward compatibility, a big deal, & technically difficult (Gaming)

by JComboBox, Friday, June 19, 2015, 02:29 (3445 days ago) @ Cody Miller

Actually, my understanding is that the Xbone natively runs a hyper visor (some VM host) that nominally runs at least 2 virtual machines concurrently. One is devoted to games and the other devoted to applications etc. That's why you can switch between applications and games while they run in parallel. This also allows the Xbone to perform basic VM trickery like saving the state of an entire VM so that when you turn the box off and on you literally pick up your game where you left off.

I imagine that they are simply wrapping the 360 games with an emulation VM that is designed to run on the Xbone Game VM (or possibly dynamically load a separate 360 VM).

This is why I choose Xbone over the PS4. At the end of the day, Microsoft is a huge company of talented software developers that, once management allows, can bring the latest and greatest software design to the console. In fact, Microsoft is going through a little software renaissance if you ask me. Sony has always been fairly poor in the software department I think.

Also, your JIT angle does make some sense, however they generally go a little lower and compile out object code first. For Microsoft this is their .Net framework which copied Java (which copied someone else etc) wherein the more a program runs, the better the hosted code performs as it learns how your code is executed.

FYI it makes benchmarking performance in Java and .Net fairly annoying :)