P
Paul
http://en.wikipedia.org/wiki/Compositing_window_manager(PeteCresswell) said:
"The most commonly used compositing window managers include:
...
Microsoft Windows - the Desktop Window Manager"
http://en.wikipedia.org/wiki/Desktop_Window_Manager
"Desktop Window Manager is the window manager in
Windows Vista, Windows 7, and Windows 8 that enables
the Windows Aero graphical user interface and visual theme."
http://en.wikipedia.org/wiki/Windows_Aero
"Use of DWM, and by extension the Aero Glass theme, requires
a video card with 128 MB of RAM, supporting pixel shader 2.0,
and with WDDM-compatible drivers."
That kinda hints at things, but in true Wikipedia fashion,
doesn't spell it out.
On a "traditional" OS, a program draws into a window. A window
is a rectangle, with a pixmap in it. No transformations are applied,
with the exception of perhaps an (X,Y) offset to the rectangle's
origin on the screen. And perhaps clipping of parts that aren't visible,
that sort of thing. The clipping might be implemented by
CPU calculations, and the GPU would be used as a "dumb frame buffer".
The GPU doesn't get warm, because it's not accelerating or rendering
anything.
A "compositing" window manager, is a transformation of the rectangle.
The program thinks it's drawing into a rectangle, but all the
rectangles are stored in graphics card memory (the 128MB requirement).
Once in the graphics card memory, transformations can be applied to
the windows, such as, say, painting the windows on the six sides
of a 3D cube. That would be an example of a transform applied to each
pixmap, before it appears in the viewable frame buffer for the user
to look at.
Other kinds of transformations the running programs might not be
aware of, is if the window is "fogged out" to indicate it doesn't
have focus. The program didn't draw a "fogged out" window, the
display manager applied a transformation to the program's rectangle,
to change the opacity or other visual properties. The GPU did the
transform. Perhaps the programmable shaders implemented the
transform.
The Mac did this with Quartz (managed rectangles in GPU memory),
and the last Mac I bought had about the same graphic requirements
for compositing of windows. In Linux, Compiz is the equivalent
of these kinds of effects, with the inclusion of cheesy effects
such as the "exploding" window when you dismiss a window.
http://news.opensuse.org/wp-content/uploads/2007/08/animation-explode.png
*******
" - It looks like Premium does not support multiple CPUs....
My boxes have 2 CPUs... but I don't know enough to tell for
sure if that's a deal-breaker. Sounds like one on the
surface though..."
Your box may have two cores. Less likely to have two CPU sockets.
They count sockets now.
When WinXP came along, the licensing scheme changed in terms
of CPUs and cores. This page provides a summary for Windows 7.
http://windows.microsoft.com/en-US/windows7/products/system-requirements
"PCs with multi-core processors
All 32-bit versions of Windows 7 can support up to 32 processor cores,
while 64‑bit versions can support up to 256 processor cores.
PCs with multiple processors (CPUs):
Windows 7 Professional, Enterprise, and Ultimate allow for two physical processors
Windows 7 Starter, Home Basic, and Home Premium will recognize only one physical processor."
The second requirement is the most strict, and is consistent with
the change that came along with WinXP. They started using "sockets"
on the motherboard, for licensing. WinXP Pro allowed the use of
two "sockets" or a dual socket motherboard. You were allowed to
stuff any core count you want in each socket. Windows 7 Pro
appears to allow two sockets as well.
This would be a "2 CPU limit"
ftp://ftp.tyan.com/img_mobo/S8236-IL_2D.jpg
Each of those sockets, can hold a 16 core processor. For a
total of 32 cores. This is an example of a reasonably priced
processor for those sockets.
http://www.legitreviews.com/images/reviews/1741/amd-fx-zambezi-17.jpg
http://www.newegg.com/Product/Product.aspx?Item=N82E16819113036
Paul