slow global undo system

I’m sure this has been asked or brought up before - but why is global undo (ctrl-z) so slow?? I have my undo levels at 40. If I hit ctrl-z after moving, rotating, deleting any object, I have to wait several seconds for the undo to occur.

I’m running a C2D E4400 (2.0ghz) with 2gb ram and GF 7500LE 256 on Vista home premium with all the goodies turned off (classic Win2K looking windows).

For me, it’s realtime (except when I’m working with extremely dense meshes).

For me it works instantly, are you working on big meshes or it occurs also in simple scenes?

It’s a relatively heavy scene, but not that bad I didn’t think. About 420K polys, amongst around 50 objects.
instantly within simple scene like the default.

I don’t know, but there is some slowdown when working with dense meshes, so it might be normal. I know not to hope that selecting edgeloops on dense mesh will be realtime…
I have a mesh with almost 40k faces and armature and subsurf modifiers enabled only for rendering and it takes few fractions of second to undo one step, but my comp is not that powerful as yours. The undo step might take some time, because it has to fish out the right data from memory. Check how processor is used while undoing to know, if the lag is caused by computational complexity or the amount of of data.