High speed precessionally switched magnetic logic devices and architectures are described. In a first example, a magnetic logic device includes an input electrode having a first nanomagnet and an output electrode having a second nanomagnet. The spins of the second nanomagnet are non-collinear with the spins of the first nanomagnet. A channel region and corresponding ground electrode are disposed between the input and output electrodes. In a second example, a magnetic logic device includes an input electrode having an in-plane nanomagnet and an output electrode having a perpendicular magnetic anisotropy (PMA) magnet. A channel region and corresponding ground electrode are disposed between the input and output electrodes.