Re: Window resizing _very_ slow with compiz
Window resizing with Composite is slow because every time the window is resized, the server creates a new pixmap (which starts out in system memory by default) and then copies the contents of the old pixmap into it, which does a readback from video memory. Then, when compiz creates a texture for that pixmap, that uploads it to video memory again. This is clearly inefficient. You can improve resizing performance considerably by setting InitialPixmapPlacement to 2 so that all that's required is a fast vidmem-to-vidmem blit. However, most of the time the copy is useless anyway because the application will repaint the entire window in response to a resize.