Socket P VS. socket 478

how much smaller is a Socket P compaired to a standard 478 socket. The Socket P is a mobile socket** I need a water block that will fit a Socket P (479)

The sockets are physically identical in dimensions and I believe that a Socket 478 processor will actually fit in a Socket P socket (although it is not electrically compatible and will not run.) One word of caution though- just because the sockets are identical doesn't mean the heatsink bolt holes will be identically-spaced. I don't even know if the bolt holes are spaced the same on different Socket P motherboards as most are highly proprietary laptop motherboards. I would measure your motherboard's heatsink bolt holes very carefully and look to see if a Socket 478 water block will fit.

Good luck! I hope you post pics of the final product, it should be VERY interesting .

That will def be a dual battery jobby !!