Cray XD1

The Cray XD1 is a specialized system with 6 dual opteron compute blades, with FPGA-based custom interconnect adapters by Cray, connected by a Mellanox Infiniband switch chip. The FPGA's are directly connected to the opteron processors via Hypertransport, so this is the currently the only InfiniBand-based system that does not use a mellanox adapter chip we have.

Peak Bandwidth on XD1 vs InfiniBand and Dolphin SCI (SISCI)

Interconnect small message latency