Excessive power usage with external monitor since version 280
I'm using a Lenovo T410 under Linux (NVS 3100M chip). With driver version prior to 280 it was easily possible to give a 90 minutes lecture using a beamer. Since version 280 and above my battery is empty after about 60 minutes with exactly the same setup. This happens regardless whether the beamer is attached via VGA or DisplayPort. Switching back to 275 and everything is fine again. This looks like a huge bug to me.