The MPP
devices all implement
MPI on top of native communication. For the devices whose names start
with with ch_, the device uses the simpler channel interface,
minimizing the amount of platform-dependent code. For the other
devices, the ADI is implemented directly on the native communication
library.
For all MPP devices, MPICH uses the native mechanism for starting and managing processes, for handling I/O, etc.
The performance of these MPICH implementations is in most cases very close to that of the underlying communication layer.