I have a customer with a 640MB BFG 8800GTS graphics card.
He plays a lot of games.
He already has a 22" monitor attached but want's to add another one.

He has an MSI P7N 750i SLI motherboard.

The question is. Will a second monitor slow down the card for gaming?

or

Does he add a cheap second card (not linked via SLI) to output to the second monitor?

Comments and advice gretfully appreciated.