0

On my system, this is a problem if you have a 3D application with running, which takes some time to redraw, and drag any window over it. It causes a very jerky movement. This also happens if you drag a dialog from the 3D app over its 3D window. The application actually gets a redraw message (WM_PAINT?) which causes it to do a full redraw. Shouldn't the background window be cached by Windows as a bitmap or something?

I've pasted the NVIDIA system information dump below, note that I have 2 GPUs. Don't know if that's significant, but we're seeing this problem on another machine in the office, which also has 2 GPUs and Windows 7. Other machines which have 1 GPU don't have this problem.

foijord
  • 76
  • 4

1 Answers1

1

Found out what the issue was. I was running Windows Vista Basic color scheme, instead of Aero. In basic, Windows probably only has one buffer for the whole screen, so whenever a window is moved, any window it overlaps must be redrawn. In Aero, each windows' "buffer" is cached to enable gpu accelerated blending (for the transparent parts of the window). So in Aero, there's no redraw of underlying windows as a result of dragging another window across it.

foijord
  • 76
  • 4