what is better xd-h picture card or xd-m picture card?

Answer 1

xD-M cards are Olympus' standard format xD cards. These are the ones you will usually find in stores. The xD-H (which is what I have for my SP-310) is a high-speed xD card, which is supposed to make viewing pictures and taking burst shots quicker as opposed to the slower "M" type card.

I haven't noticed that much of a difference, personally.