it maybe 16gb, buts its rated at 2 mb write. Thats damn slow! Thinking about putting my 8gb with a write speed of 6mb... Just dont know how much it matters our not. I would guess it does, but as the phone seems to be speedy don't know if it will change to much. Have to play around with more photos and see.
Just look at that little circle and see the number in it. (2). Every SDHC card has to have a speed rating.
http://en.wikipedia.org/wiki/Secure_Digital