A:Answer Anything over 2 Gig is overkill. The card is used to store games or channel lists. The Roku is a streaming device only, which means you can't download video to the card. There are some exceptions such as a couple of apps that allow you to download videos you've rented or purchased. However, there aren't many. To answer your question straight out, I believe the Ultra can handle a 64 Gig card, but using a card that big is just a waste of storage, IMO.