@Dragster
Using the VRAM monitor I described above, I made some experiments and, when I overloaded the VRAM by opening lots of drawers and applications I noticed a kind of "swapping" effect : when I ran very low of VRAM (typically above 60MB used out of 64), I noticed a short freeze followed with a big flush of the VRAM that went back to around 40MB used, without me doing anything. I concluded from that that, for performances enhancement, MOS keeps a graphic copy of each drawer or application we open into its VRAM, even when masked, but flushes this copy if the original is not visible, when necessary. As a result it has to "rebuild" its layout when the drawer or the application is unmasked.
So yes, the more VRAM you have, the better
Though, of course, you could certainly overload 256MB too. But setting my color-depth to 15/16bits kept my medium VRAM use under 40% all the time and I never suffered again from those short freezes that occur during the flushes. And FigRoll having only 32MB of VRAM I guess his high-resolution will certainly prove painful an experience.
