Should I dress up for conference banquet/gala dinner? I am thinking about what should I bring to the conference.

Normally, will people dress up (like full suit) for the dinner?

p.s. I am in CS domain.
No. You do not need to wear a suit for presenting at a conference. Most of the times, CS conferences have the typical t-shirt (or shirt), jeans combination of computer / tech guys. 

For the dinner, you can dress a little more formally (if you want) but still a suit is not required. In fact, if you are young (&lt;30) , wearing a suit and a tie would probably seem a little weird. 

Bottom line: Wear what you usually wear when you go to work for the presentation and a little more formal (nicer) wear for dinner.