An FPGA-Based Custom High Performance Interconnection Network

An FPGA-based prototype of a custom high-performance network hardware has been implemented, integrating both a switch and a network interface in one FPGA. The network interfaces to the host processor over HyperTransport. About 85% of the slices of a Virtex IV FX100 FPGA are occupied and 10 individual clock domains are used. Six of the MGT-blocks of the device implement high-speed links to other nodes. Together with the integrated switch it is thus possible to build topologies with a node degree of up to 6, i.e. a 3D-torus or a 6D Hypercube. The target clock rate is 156 MHz with the links running at 6.24 Gbit/s and 200 MHz for the HyperTransport Core. This goal was reached with a 32-bit wide data path in the network-switch and link blocks. The integrated switch reaches an aggregate bandwidth of more than 45 Gbit/s. The resulting interconnection network features a very low latency – between nodes and including switching - close to 1 µs.