More on Longhorn graphics architecture

[Jon Smirl]

"What does this actually mean? 3D surfaces can be paged out to virtual
memory as needed. This is critical in the Longhorn user interface,
where every window will be a 3D surface. Applications can now be
bigger than graphics card memory currently allows. Of course, this
also implies that performance in older AGP-based systems—even those
with beefy graphics hardware—may be limited by the write performance
over AGP. AGP was never meant to be a fully duplexed pipeline, so
upstream performance is pretty poor. PCI Express, with its robust
two-way communication, should work well.

Virtualization extends to the idea of cross-process shared
surfaces—two applications running different surfaces can share surface
data. Again, this is useful when running the Avalon Desktop Window
Manager. Virtualization comes at a cost, though. Instead of the 128MB,
256MB (or now, 512MB) frame buffer, graphics can consume an
effectively unlimited amount of memory, so be prepared to buy systems
with lots of main memory!"

http://www.extremetech.com/article2/0,1558,1791681,00.asp

-- 
Jon Smirl
jonsmirl at gmail.com