GPU Clock issue when on AC Power

[ts1506]

Hi all,

I am using an Asus Laptop (X200CA-KX219D) with the following specs
Intel Core i3-3217U
4GB 1600MHz DDR3 RAM
Intel HD4000

I am facing a weird issue, my GPU clock would get locked to 350MHz (lowest) whenever I plug in to power. When gaming, this is a nuisance, as fps is much lower than it ought to be. If I run games on battery, the GPU acts fine, and stays at 1050Mhz (highest) as its meant to be. 

I have tested various games to make sure that its not a game-specific issue (tried Tomb Raider, NFS Run, Bioshock Infinite, GTA 4, Sleeping Dogs, AC4, Titanfall). All the mentioned games run the GPU at max clock on battery, but get locked to 350Mhz on power.

I have also made sure that my laptop isnt thermal throttled.

Power profiles are correctly set up, and the GPU is set to maximum performance in all profiles.
I am on the newest Intel HD Driver (15.33.22.3621) and on the newest BIOS for my laptop. Apart from this issue, my laptop is performing fine in everything else.

Thanks in advance.