Created attachment 111966 [details]
elemental stalls near end with large vram -> gtt move

Generally the new version is a bit better, it's still not right, it has
glitches but they are shorter.

I have 8 Gig ram now so can run from tmpfs to exclude the glitching being
caused by disk activity. 

There is sometimes a new issue very near the end where there is a chance of a
multi second stall corresponding to vram -> gtt move as in the screenshot.

This didn't happen at all the first couple of times I tested.

The third time only 200meg was moved the fourth is this shot.