If i plugged my monitor into the motherboard would it make a massive difference? my specs are; graphics card :gtx 660 ti sc motherboard :asus p8z77-v Processor: i5 3750
It depends on what you are doing.
For normal desktop work, web browsing, HD movie playback, there will be little difference.
But... presumably, you bought a GTX660ti, a fine graphics card, for gaming. If you are gaming, attaching your gaming monitor to the discrete card will make all the difference in the world.