HP Cluster Platform Interconnects v2010 Quadrics QsNetII Interconnect - Page 31

Figure 3-4: QM501 Switch Card Each of the 16 downlinks of the first stage of switches connects to a QM500 network adapter. The 4 uplinks of each Elite in the second stage of switches connect to QM502 downlinks. 3.3.2 QM502 Switch Card The QM502, shown in Figure 3-5, is a switch card containing four Elite switch components. It provides 16 ports to implement the third stage in the fat tree topology. Figure 3-5: QM502 Switch Card Depending on the interconnect configuration, Each QM502 provides the following links: • 4 downlinks only. The 4 uplinks from each of the 4 Elites in a QM502 switch card are unused in a bounded configuration (less than 128 nodes). • 4 downlinks and 4 uplinks. Each downlink connects to one of the four QM501 16-port switch cards housed in the node switch. The uplinks connect the node switch to the top-level interconnects. 3.3.3 QM511C Switch Card The QM511C, shown in Figure 3-6, is a switch card containing seven Elite switch components. It provides 16 ports and implements all three stages in the fat tree topology of a single interconnect, supporting a cluster of up to 128 nodes. 128-Port Interconnect Modules 3-7