[WizOSX]

It seems to be the consensus here that using an external monitor dedicates half of the VRAM to internal monitor, half to the external. This means that on a 16mb VRAM iBook, each monitor only gets 8mb. If so, then Quartz Extreme shouldn't work properly. Am I right?

[Luca Rescigno]

OS X will disable it, however, if you go here, it will show you how to change the minimum VRAM settings for QE:

After this patch Quartz Extreme will not be active while using two screens if you have a machine with 16 MB VRAM. This is the same problem as with the Powerbook G4 with 16 MB VRAM. You can fix this issue by changing the value of

GLCompositorMinimumVRAM

in the file


System/Library/Frameworks/ApplicationServices.framework /Versions/A/Frameworks /CoreGraphics.framework /Versions /A/Resources /Configuration.plist
from 16 to 8.

You need special privileges to save changes to this file. You can either do it in OS 9 or log in as root. You can also temporarily change the owner of the file. Use the "Get Info" command in Finder to make yourself owner of the file (remember who owned it before). Then open it with any plain text editor or, if you have the Developer Tools installed, with "Property List Editor". Change the value and save the file. Now you can change the owner back to the one originally set.

[OreoCookie]

That is if you use monitor spanning. If you use mirroring, it is active.

But beware, having only 8 MB video RAM means that QE doesn't have to be faster than Quartz ...

[selowitch]

Originally posted by WizOSX:
It seems to be the consensus here that using an external monitor dedicates half of the VRAM to internal monitor, half to the external. This means that on a 16mb VRAM iBook, each monitor only gets 8mb. If so, then Quartz Extreme shouldn't work properly. Am I right?

Does this mean that a current iBook G4 (with 32MB VRAM) will be able to leverage Quartz Extreme when using an external display?