Intel HD Graphics 4600 (Asus G750JM) connected to BENQ XL2420T (120Hz capable monitor) via Displayport would only go up to 1920x1080 @100Hz and no option to go @120Hz.

Hi

I have an ASUS G750JM running i7 4710HQ and 2 GB Nvidia GTX 860m with Intel Graphics 4600 integrated.

I recently bought a BENQ XL2420T which supports 120Hz refresh rate.

On the display settings, connected via mini displayport to displayport cable, it can only go up to 1920x1080 @100Hz. There is no 1920x1080 @120Hz option.

Please Help.