lspci -nn | grep VGA

00:02.0 VGA compatible controller [0300]: Intel Corporation 3rd Gen Core processor Graphics Controller [8086:0166] (rev 09)
02:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Thames [Radeon HD 7550M/7570M/7650M] [1002:6841]

$sudo cat /sys/kernel/debug/vgaswitcheroo/switch
    0:IGD:+:Pwr:0000:00:02.0
    1:DIS: :DynOff:0000:01:00.0

$cat /proc/version_signature
    Ubuntu 4.4.0-24.43-generic 4.4.10