I'm looking at these 2 graphics cards. Both are 8800 GT cards.

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=3606193&CatId=3668

and

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=3525730&CatId=3670

The 1st card says it has 256MB GDDR3
and th 2nd card says it has 512MB GDDR3

What does that mean? In terms of frame rate and graphics?

I would assume the more "stuff" the better? 512MB is better then 256MB.