A new release candidate of MPICH, 3.3rc1, is now available for download. MPICH 3.3 contains a new (non-default) device layer implementation – CH4. CH4 is designed for low software overheads to better exploit next-generation hardware. An OFI (http://libfabric.org) or UCX (http://openucx.org) library is required to build CH4. Example configure lines:
./configure --with-device=ch4:ofi --with-libfabric=<path/to/ofi/install>
./configure --with-device=ch4:ucx --with-ucx=<path/to/ucx/install>
Unless critical bugs are found, this release would be identical to the final 3.3 GA release (apart from the version number change).