Now I think the mb/s is to do with the speed it is capable of updown loading the picture to the card,  and the Gb is the storage capacity , that as I understand it tends to range from 1Gig to I am not sure?  Often as high as 64Gig 
But I get what you mean about having more smaller ones  compared to one large one , as if you have a load of smaller ones you could use one for each day,  making editing easier I would have thought,  
Will be interesting to see the answers from the,  tech guys that we have on here 

If at first you don't succeed,  don't be frightened to ask,  life is too short to make all the mistakes yourself. 


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