How much VRAM does an external 1680x1050 display use?

[aliquis-]

I link form here aswell in case some people aren't browsing the MBP forum but this one:
https://forums.macrumors.com/threads/341682/

 

[gnasher729]

I link form here aswell in case some people aren't browsing the MBP forum but this one:
https://forums.macrumors.com/threads/341682/

Very little of the VRAM is actually used for the actual displays; that would only be 1680 x 1050 pixels x 4 byte = about 7MB. Most of the VRAM is used for the contents of windows and for gamers VRAM is used for textures; you would tend to have more open windows with two monitors, and a giant window covering both monitors would use more VRAM. You can download something like Virtue desktop which lets you have say four virtual desktops; you would have exactly the same effect on VRAM usage, so if virtual desktops run fine, then two monitors run fine.

 

[aliquis-]

Very little of the VRAM is actually used for the actual displays; that would only be 1680 x 1050 pixels x 4 byte = about 7MB. Most of the VRAM is used for the contents of windows and for gamers VRAM is used for textures; you would tend to have more open windows with two monitors, and a giant window covering both monitors would use more VRAM. You can download something like Virtue desktop which lets you have say four virtual desktops; you would have exactly the same effect on VRAM usage, so if virtual desktops run fine, then two monitors run fine.

I doubt the virtual desktop uses vram when not shown thought, but for two screens one can't be hidden and therefor never drawn so probably not the same.

So vram isn't shared between screens? I read in bare feats review that the 256MB modell might be good for 30" ACD because then the screen would use/get 128MB.

I know each window will take up the equivalent of bitmapped graphics usage, do you know if that is also true for minimized windows? Or do those lose that information from vram and are redrawn ones you open them up again? It is always true for open Windows even if they are hidden beneath another?

The thing is I can't decide if I should go with 128MB vram 2.2ghz mbp or 256mb 2.4.

I want 256MB and I think it's the logical setup to use but since Apple are stupid and only ship with 128MB on the cheapest modell 128MB more vram comes as such a premium and I don't give a rats ass about the CPU (or well I do, I care a lot and I hate it.. ;D)