Why is the Fuji RAW file bigger than Sony and Olympus?

I'm curious where you got your numbers for pixel count.  The manual lists 4896x3264 as the maximum resolution and every shot that I have taken (raw only and raw plus all the forms of jpeg) I get a raw image size of 4896 x 3264.  This is using Photoshop.  Do other raw processors produce different results? Or are we talking about different cameras?  I am using the XE1.