On some secondary GPUs they report that they have the VGA port enabled. This has been seen on the GeForce GT 520M.
Symptoms include higher drain on the battery, fans constantly running, Xorg attempting to treat the discrete card as a secondary monitor.
This issue can be detected by opening a console and typing xrandr
:
[root@localhost ~]# xrandr
Screen 0: minimum 8 x 8, current 2390 x 768, maximum 32767 x 32767