Basic Questions about Xbox One that have already been discussed to death before *spawn*

Well, if the games were to run within the Windows environment on the box, then you have a threaded multitasking type situation. Having the game and OS run in seperate light-weight VMs using hardware virtualization is a different way of managing resources. I imagine each has its own pluses and minuses.

I'm guessing they believe it would lead to more consistent performance guarantees for games.
 
Why have 3 operating systems

Well, if the games were to run within the Windows environment on the box, then you have a threaded multitasking type situation. Having the game and OS run in seperate light-weight VMs using hardware virtualization is a different way of managing resources. I imagine each has its own pluses and minuses.

I'm guessing they believe it would lead to more consistent performance guarantees for games.

1. being able to innovate GameOS/HostOS/SharedOS independently of each other at different cadences ..
2. better backwards compatibility / versioning story
3. as Scott mentioned QOS Guarantees

Who knows what it will look like when Windows 10 arrives, lots of the innovation MS made with Xbox OS's in Windows 8 will somehow need to make their way into Windows 10. Some believe lots of the changes underpin Windows 10 and that phone/tablet/desktop etc will get these changes too ..

p.s. we may move back to a single OS that can do it all via "Windows Containers" - I wrote about it in this post reply
 
Why have 3 operating systems

  1. Secure Isolation: isolating applications so that an ill-behaved application can't compromise other applications or its host.
  2. Persistent Compatibility: allowing host and application to evolve separately. Changes in the host don't break applications.
  3. Execution Continuity: allowing applications to be freed of ties to a specific host computer. A running application isn't tied to the computer on which it was started, but can be moved from computer to computer across space and time within a single run.
  4. All without the large resource overhead VMs typically need.
Even if the Xb1 OS isn't a derivative of Drawbridge, I still think both are product of the same motivations.
 
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2. better backwards compatibility
But the xb1 has no backwards compatibility

Execution Continuity: allowing applications to be freed of ties to a specific host computer. A running application isn't tied to the computer on which it was started, but can be moved from computer to computer across space and time within a single run.
but you never move programs from 1 xb1 to another

All without the large resource overhead VMs typically need.
why is that ?
 
But the xb1 has no backwards compatibility


but you never move programs from 1 xb1 to another


I'm more talking about future iterations of the console or xbox devices.. technically a Title written on day one eg. Forza 5, which ships with its own os/drivers/dx etc. should be able to run in year 10 on the same xbox as well as hopefully on the next xbox (assuming we get another one) ...

Just like the back compat story for apps on windows .. rather than having to support api's for several generations via versioning and weird interface naming, we can use virtualization to solve this problem.
 
but you never move programs from 1 xb1 to another

Transmedia ramifications. This feature may not exists now but probably will in the future. Moving from your XB1 to the cloud so that you can play your games remotely in a more seamless fashion.

why is that ?

We have no ideal how the XB1 OS is actually configured but if its anything like Drawbridge then its not running three complete OSes.

Drawbridge is virtualization on the OS level not hardware level. Only the Host OS is sporting an OS kernel. The library OSes house the application services that make calls to a dynamic link library that is part of a kernel emulation layer that exists within the library OS. Calls are passed to and through the security layer to the kernel of Host OS below. Anything above the security layer runs in user mode while everything below runs in kernel mode.

When MS refactored Win7 for Drawbridge, the library OS of windows 7 was only 64 MB of binary requiring 16 MB of working memory, which is a lot lighter than the 512 mb of RAM and 4.8 GBs of disk space win7 requires when running as a guest OS on top of HyperV.

http://channel9.msdn.com/Shows/Going Deep/Drawbridge-An-Experimental-Library-Operating-System

The video goes into drawbridge's structure, how its different from vanilla windows/VMs and demos drawbridge running win7 and excel. They run excel locally then upload to cloud and access the spreadsheet remotely through IE.

That being said, the XB1 OS is structured differently than Drawbridge. Where as the user services in Drawbridge are part of the Host OS than runs above the security level, the XB1 has a third OS that house the user services and its Host OS doesn't seem to operate above the security layer/hypervisor.

Drawbridge was prototyped on the xbox 360 hardware at one point.

http://www.zdnet.com/article/microsoft-midori-mention-makes-it-into-new-research-presentation/

Nevertheless, the XB1 may be an evolution of drawbridge or might be an outright departure and based on other research.
 
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