Talk:Dell Latitude E7440
"After a very long research and several tens of reboots I came up with the conclusion that if you power on the laptop without having AC connected the overall GPU performance will be WAY worse than if you did with the AC connected. It does not matter whatsoever if you connect AC afterwards - GPU/OpenGL/drawing _IS_ going to be slow once you've started it without AC."
-> I'm facing exactly the same problem. I thought this appears when I upgraded gnome-shell to the last (3.12) version. What about you ? Did you finally solve this issue ?