=====Tiger=====
Tiger is a Cray XD1. It has 72 nodes, each with two 2.2-GHz AMD Opteron processors and 8 GB of memory. Seventy of the nodes are in the compute partition, and 6 of those nodes have Xilinx Virtex-II Pro field-programmable gate arrays (FPGAs) connect as co-processors through a Hypertransport interface. The Cray RapidArray Interconnect connects the nodes, also through Hypertransport, and provides high bandwidth and low latency for interprocessor communication.All the nodes run Linux, but the compute nodes have a special kernel that allows them to synchronize with a global clock and co-schedule processes to avoid latency in global communication.