Input Lag Issue

I'm having a strange issue with input lag. Originally I played SF4 on my laptop, but realized my laptop screen had some amount of lag higher than tournament standard. I decided to get a BenQ Gaming Monitor RL2455HM (24-Inch LED). However despite getting this monitor and connecting it to my laptop I'm still experiencing input lag. I can feel the difference playing on a xbox with an ASUS or other peoples' desktops using a BENQ.

It seems like the laptop display is exactly the same as the monitor display when I duplicate the screen view (and taking a picture with a camera confirms this).

I have no idea why this is the case. Definitely really frustrating, please help.

Thanks

EDIT: My BENQ is having problems when connected to my laptop.