ok the thread is kinda old.
I know this "graphical effect" in some games this bar moves down when framerate goes down and the other way round.
Try other SLI-modes could help. (change in nvidia control center or with nhancer)
With nhancer you can deactivate SLI with one click.
In the registry I changed only
So i can use both.
right mouseclick on the desktop = old controlpanel
right mouseclick on taskbar icon = new controlpanel