Is there a benefit to running two 512mb video cards as opposed to a single 1gb vdeo card?

Or is 1gb pretty much just 1gb?|||Yeah except you forgot the other video cards steam processors which makes a huge difference. The way I see it is that your thinking about it like RAM which one 1GB stick vs. 2x512MB sticks but you forgot a video card is a lot more than just memory.|||SLI capability?