Nikon D800 FPS rate in medium image size

A Question for those Nikon D800 owners out there. I know the D800 has a 4fps at maxium RAW file size. But If one reduced the image size down from large/fine to medium/fine image size FX (20.3MP) RAW does the frame rate speed increase some what over the quoted 4fps at 36.3MP?

The reason why I am asking is that the D600 has a 5.5FPS at its maxium 24MP and comparing the D800 at a lower image size its FPS for shooting topside subjects like Whales and Dolphins.

Also what is the size of the buffer of the D800 at maxium Fx, Medium Fine FX, and also Maxium DX (Large Fine DX)

Regards Mark

Here is a high frame rate example from the D800 - 36MP/14bit/RAW. While it doesn't offer world beating frame rates, it is also no slouch at capturing multiple frames of action.

Alex