That's correct. Just don't mix up Mb (=Mega Bit) and MB (=Mega Byte).
So a Class 6 SD(HC) card can transfer Data at min. 6MB/Sec. With a fine-jpeg size of 4MB that's only 1.5 pictures per second sustained tranfer rate.
And with RAW+jpeg you'll end up at 12-15MB per picture that means 0.5 pics/sec sustained transfer rate.
So to really keep the data flowing you should invest in some technology that goes to at least 20MB/sec
Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews
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