which cable is better for gaming? HDMI or VGA Cable and also which HDMI Port on back of X51

ok guys I think it is a simpe HDMI But want to know for certain. I have the X51 and have been playing IRacing nonstop since I got my X51 in march.

I have been using a Vizio 22'' LCD TV with a Mini HDMI cable plugged into the Graphic card in the back. I didn't like the vizio that much cause I had a bunch of trouble getting the video to fit the screen correctly and be clear. IT just didn't work well I ended up getting it stretched out but it never did fill the entire screen as there was a black border it never did use all the screen.

Just got a Samsung LED 24'' monitor. It came with a VGA cable so that is the reasoning for the first question. hopefully this monitor will work better for me than the tv did

and for the second question. which HDMI port are you using on your X51. I have been plugged into the graphincs card.

Is there a noticeable difference in the two?

anyways let me have those opinions     thanks nathan