My new Dell Inspiron I7773 laptop has an SD card slot, and I'd like to put a fast 128 GB or larger card in it to play video files when I go portable with it occasionally. However, I can't seem to find out if there is a capacity upper limit (in GB) or speed class limit and don't want to purchase one only to discover that I've spent serious $$ on a card that the computer can't use. Please, can anyone tell me what card size/type to buy? Thanks in advance.