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#1
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Is there a technical reason why there's no DirectX 10 & 11 for XP?
Is there a genuine technical reason or is it just Micro$oft pushing you to their next offering?
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#2
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Is there a technical reason why there's no DirectX 10 & 11 forXP?
Doc wrote:
Is there a genuine technical reason or is it just Micro$oft pushing you to their next offering? There are some differences, but we can pretend they were introduced for business reasons, and not for some technical reason. There is no particular reason to continue compositing windows, while your favorite 3D game owns the whole screen, but that's how they made it work. They could have just paged out the desktop when a user wanted to game. http://en.wikipedia.org/wiki/DirectX "Direct3D 9Ex, Direct3D 10, and Direct3D 11 are only available for Windows Vista and Windows 7 because each of these new versions was built to depend upon the new Windows Display Driver Model that was introduced for Windows Vista. The new Vista/WDDM graphics architecture includes a new video memory manager supporting virtualization of graphics hardware for various applications and services like the Desktop Window Manager." http://en.wikipedia.org/wiki/Desktop_Window_Manager "Architecture The Desktop Window Manager is a compositing window manager. This means that each program has a buffer that it writes data to; DWM then composites each program's buffer into a final image. By comparison, the stacking window manager in Windows XP and earlier (and also Windows Vista and Windows 7 with Windows Aero disabled) comprises of a single display buffer to which each all programs write." I think what that means, is video card memory is used to hold each program window. Whereas, in the earlier graphics implementations, each program window is held in system memory, and video card memory only holds the final (frame buffer) image. And as far as I know, when you play a 3D game on a DWM enabled system, the desktop compositing is still held in the video card while the game plays. Even though you can't see the desktop at the time. The video card memory probably has less than 128MB held up doing that. (So if you're gaming with a 512MB card on a DX10 system, some of that memory is being "wasted".) On a DirectX 9 system, when a game starts to play, I think the game basically "owns a display channel". Whereas in the DirectX 10/WDDM/DWM world, the access is no longer exclusive, and the game actually shares some resources with other things on the computer. Your desktop display is "alive", but you just can't see it. This is a good reason to have a bit more video memory on the video card, and at the same time, switch to 64 bit operation so you don;t run out of address space while doing so. I'm not convinced they had to do it that way. They could have retrofitted the new display ideas onto the old architecture, if they wanted. The video card is flexible enough from a hardware standpoint, you could have done things either way. Paul |
#3
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Is there a technical reason why there's no DirectX 10 & 11 for XP?
From: "Doc"
Is there a genuine technical reason or is it just Micro$oft pushing you to their next offering? The latter. It is their way of forcing an OS EoL. -- Dave Multi-AV Scanning Tool - http://multi-av.thespykiller.co.uk http://www.pctipp.ch/downloads/dl/35905.asp |
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