Direct3D vs. OpenGL

[Sinc]

Prior to 2008, when I installed Autodesk products on our systems (using nVidia Quadro graphics cards), the default setting for the video drivers was OpenGL. Now in 2008, the default settings are Direct 3D.

In my experimentation, I seem to be getting FAR FAR FAR BETTER performance from the OpenGL drivers. Is this expected? If so, why did Autodesk change the default drivers to the Direct 3D drivers? If not, what would be causing my OpenGL drivers to perform so much better than the Direct 3D?

To simplify matters, assume I am using the v9136 drivers on a Quadro FX1500, although we seem to be seeing the same behavior with all our nVidia graphics cards.

[kspear]

This seems to be in keeping with VISTA compatibility. By default, VISTA graphics is set to directx. I'm sure someone else knows the reasons why. You'll see them same thing with Google Earth, which wants to switch to directx mode. As long as you're on XP, OpenGL, IMO, is the way to go, as your experiment proves out.

Kevin

[Neilw_05]

I believe that you will need OpenGL to generate 3D DWF's as well. Vista is
built on Directx. It seems Autocad is going to have to transition to Directx
in the near future.

wrote in message news:5579018@discussion.autodesk.com...
This seems to be in keeping with VISTA compatibility. By default, VISTA
graphics is set to directx. I'm sure someone else knows the reasons why.
You'll see them same thing with Google Earth, which wants to switch to
directx mode. As long as you're on XP, OpenGL, IMO, is the way to go, as
your experiment proves out.

Kevin

[Anonymous]

In Vista, DirectX appears to be my only option for hardware acceleration in
AutoCAD. There was a rumor floating around that OpenGL was not supported at
all in Vista, but this has turned out to be FUD. I'm not sure why AutoCAD
doesn't allow me to choose anything other than DirectX in Vista - perhaps my
video card driver doesn't support OpenGL in Vista yet.


Jon






wrote in message news:5579018@discussion.autodesk.com...
This seems to be in keeping with VISTA compatibility. By default, VISTA
graphics is set to directx. I'm sure someone else knows the reasons why.
You'll see them same thing with Google Earth, which wants to switch to
directx mode. As long as you're on XP, OpenGL, IMO, is the way to go, as
your experiment proves out.

Kevin

[Sinc]

OK.

Sure seems strange, though. I mean, the performance is NOT EVEN CLOSE. OpenGL is worlds better than Direct 3D. Makes me wonder if moving to Direct 3D is a good choice.

[Anonymous]

If Adesk wants to stay in good grace with MS they may not have a choice.....

wrote in message news:5579281@discussion.autodesk.com...
OK.

Sure seems strange, though. I mean, the performance is NOT EVEN CLOSE.
OpenGL is worlds better than Direct 3D. Makes me wonder if moving to Direct
3D is a good choice.