1D series RAW more MB then others?

More a camera question then a RAW question, so that's why it is posted here.

Can anyone tell me if a RAW file from a 1D series or 5D is more MB and more advanced then that of a similar MP camera?

For example a 30D and 1D MKII N have around the same MP. One has better software in it for noise reduction, etc. Is the RAW file format also better in the MKIIn then the 30D?

The RAW files off my 1D MkIIN and 20D all seem to around the same size (approx 8MB). The do vary a bit however.

There's no reason it should be any bigger from the 1 series, if the pixel count is roughly the same. Unless, of course, it's the Mark III with its 14-bit color.