Transporting Distributed BLAS to the Fujitsu AP3000 and VPP-300

The DBLAS Distributed BLAS Library is a portable version of parallel BLAS that has been highly tuned for the Fujitsu AP1000 and AP+. In this paper, we describe performance enhancements made for two very different high performance distributed memory platforms, the Fujitsu AP3000 and the Fujitsu VPP-300. Even with the provision of highly tuned (vendor-supplied) serial BLAS implementations, attention must be given to cell computation speed issues, since serial BLAS does not supply a local matrix transpose routine (which is needed in many places), nor does it supply routines to adequately handle the triangular matrices which arise in the parallel context. We will describe the differing principles used on the UltraSPARC and VPP-300 nodes to optimise memory access patterns for the local matrix transpose operation and the large matrix multiply. The former uses partitioning methods which can yield a factor of 3-4 improvement of naive methods. The latter simultaneously optimizes usage of two leve..