Hi the
NB is under the silver heat sink in the middle of the board. the smaller heatsink off to the left towads the bottom is your south bridge.
If you download the manual you will find a diagram in it usually which helps locate components. Also the
NB can also be called MCP like on nforce boards.
Odd thing though, i dont see the P45 Neo-f on the msi support site, they have a couple of Neo P45s i just dont see the "F" version.