Windows 7 Way Smarter With Graphics RAM

[The Canadian]

New Windows 7 WDDM 1.1 drivers save you RAM

In an earlier article, we described an advancement that the Windows 7 team made with desktop graphics by allowing more than one application to access the GDI (graphics device interface) stack at a time.

Allowing for more parallelism in the GDI will noticeably make things more responsive, but that wasn?t the only evolution that the software team made for the new OS. Windows 7 will now be more efficient in its use of RAM, which will have the positive effect of making everything run smoother ? particularly on systems with shared graphics memory.

In Windows Vista, the more application windows you had open, the more memory required. Every window accounts for two memory allocations ? one in video memory and one in system memory ? which hold identical content.

The way Windows Vista does it

The DWM (desktop window manager) is responsible for drawing the desktop with the GPU, which obviously requires the application window data in video memory. The same application window data is duplicated again in system RAM for the CPU to render independent of graphics hardware. This was inefficient obviously because of data redundancy.

The way Windows 7 does it

Windows 7 changes this by getting rid of the system memory copy entirely, which effectively cuts the memory consumed in half. Unlike the changes to the GDI stack detailed earlier, this new memory-saving behavior requires new drivers.

?We achieved the reduction in system memory by accelerating the common GDI operations through the graphics hardware - the WDDM drivers accelerate these to minimize the performance impact of the CPU read-back of video memory,? explained Ameet Chitre, a program manager on Microsoft?s Desktop Graphics feature team. ?Since you save a lot of system memory, the paging activity gets reduced ? as a result, your system responsiveness improves for the same workload.?

The new drivers that support the memory-saving change are designated WDDM 1.1. Older Windows Vista WDDM 1.0 drivers will still work fine with Windows 7, but do not take advantage of the new feature.

Desktop Window manager memory consumption

comparison using WDDM 1.1 v. WDDM 1.0

This change positively impacts real-world usability, but benchmarks may show a degradation in performance since the CPU has to fetch data from video RAM.

?The elimination of the duplicate system memory copies which ?speed up? certain operations introduced slightly reduced performance as the CPU now has to read data back from the video memory. An analysis of real-world application statistics showed that these operations were rare,? Chitre said. ?Our observation has been that these slow-downs do not impact the end-user functionality directly and that the memory savings directly result in Windows 7 being much responsive overall. The improvements overall are definitely noticeable on memory constrained PCs with shared memory graphics.?

The close-to-completion Windows 7 is nearly upon us. We learned on Saturday that the Release Candidate will be hitting MSDN and TechNet spublic getting their Windows 7 RC download links on May 5ownload links on May 5[/url].

Source: Tom's Hardware

[Jack 0Neill]

Hopefully they release this on Vista too

[Inctye]

Hopefully they release this on Vista too

Not going to happen. As far as I am concerned, Microsoft simply wants to stop selling Vista as soon as they can and start marketing Windows 7 in every possible way to avoid it being claimed that it is the same as Vista.

[stevember]

Hopefully they release this on Vista too

Will not happen.

Not going to happen. As far as I am concerned, Microsoft simply wants to stop selling Vista as soon as they can and start marketing Windows 7 in every possible way to avoid it being claimed that it is the same as Vista.

+1 Because people listened so called techy mates that Vista was bad. MS need need change opinion. Vista on realease wasn't bad XP on realease, but Vista after SP1 a lot better any XP.

[hdood]

It's a good thing no one thought of this when they designed the DWM for Vista.

...

[Buendia]

How to know which driver is WDDM 1.1 and which is WDDM 1.0 ?

[The Canadian]

How to know which driver is WDDM 1.1 and which is WDDM 1.0 ?

Well, if you're on Vista then you've got WDDM 1.0...WDDM 1.1 will only be released to 7, as it is part of that OS.

[Ekhaatvensters]

Well, if you're on Vista then you've got WDDM 1.0...WDDM 1.1 will only be released to 7, as it is part of that OS.

So if you want the WDDM 1.1 driver go to Nvidia's site and under downloads there's a seperate Windows 7 link. The only WDDM 1.1 drivers will say win7 in the driver name.

[Yusuf M. Veteran]

Interesting. For anyone that's confused, this will only work with WDDM 1.1 drivers on Windows 7. As far as I'm aware, Windows Vista does not support WDDM 1.1.

[majortom1981]

ALSO WDM 1.1 is only for direct x10 cards. so if you have an nvidia 7xxx series you will be stuck using wddm 1.0

[Gio Takahashi]

cool, apparently, just as I read this thread, Windows 7 update just installed the driver for my Nvidia 8800 card with wddm 1.1.

Yeah, I definitely don't see this being on Vista anytime soon.

[The Canadian]

As far as I'm aware, Windows Vista does not support WDDM 1.1.

It does not.

ALSO WDM 1.1 is only for direct x10 cards. so if you have an nvidia 7xxx series you will be stuck using wddm 1.0

That should read, DirectX 10/10.1/11 cards under Windows 7....

[Buendia]

I have Ati Mobility Mobility Radeon X1350 graphics card and AMD does not provide drivers for laptop cards - my driver is probably WDDM 1.0 even though I am running Win 7 and I have downloaded driver from Windows Update. If I'm wrong, someone please correct me.

[majortom1981]

It does not.

That should read, DirectX 10/10.1/11 cards under Windows 7....

I should have put and up thanks :)

[The Canadian]

I have Ati Mobility Mobility Radeon X1350 graphics card and AMD does not provide drivers for laptop cards - my driver is probably WDDM 1.0 even though I am running Win 7 and I have downloaded driver from Windows Update. If I'm wrong, someone please correct me.

Windows 7 will still run using WDDM 1.0, however you won't see the improvements that a DirectX 10/10.1/11 (the latter not out yet) card will have. It's time for you to get a desktop....

Edited April 28, 2009 by The Canadian

[Marcus16]

So that's what that WDDM 1.1 driver update I got yesterday was. I was wondering what that was since the Nvidia drivers are the same version.

Edited April 28, 2009 by Marcus16