Implementation of Multigrid on QPACE

We developed and optimized a multigrid method on the QPACE cluster. The QPACE cluster is an acclerator-based cluster using the Power Cell 8i CPU that is built by the special research field SFB TR 55 for Lattice Quantum Chromo dynamics computations. The cluster uses a custom 3D to rus network build using FPGAs. Our goal was to evaluate the QPACE architecture for a type of algorithm that uses a communication pattern not limited to nearest neighbor communication. We provide a model of the communication network taking into account the specific characteristics of the network and the network processor. For the implementation we chose to use an accelerator-centric programming model by using the SPUs, only.