HP ProLiant BL620c HP BladeSystem c-Class architecture - Page 8

Figure 6. The blade-to-interconnect topology differs depending on your configuration. blades Interconnect Module A Interconnect Module B blades Interconnect Module A Interconnect Module B blades 6a blades 6b NonStop signal midplane provides flexibility The BladeSystem c-Class uses a high-speed, NonStop signal midplane that supports multiple highspeed fabrics. It is unique because it can use the same physical traces to transmit Ethernet, Fibre Channel, InfiniBand, or SAS signals. As a result, you can fill the interconnect bays with a variety of interconnect modules, depending on your application needs. Physical layer similarities among I/O fabrics Serialized I/O protocols such as Ethernet, Fibre Channel, SAS, and InfiniBand are based on a physical layer that uses multiples of four traces with the SerDes (serializer/deserializer) interface. The backplane Ethernet standards of 1000-Base-KX, 10G-Base-KR, and the 8 Gb Fibre Channel standard use a similar four-trace SerDes interface. Consolidating and sharing the traces between different protocols gives you an efficient midplane design. Figure 7 illustrates how the physical lanes are logically overlaid onto sets of four traces. Interfaces such as GbE or Fibre Channel need only a 1x lane (a single set of four traces). Higher bandwidth interfaces, such as InfiniBand, will need to use up to four lanes. Your choice of network fabrics will dictate whether the interconnect module form factor needs to be single-wide (for a 1x/2x connection) or double-wide (for a 4x connection). By logically overlaying the traces, our HP engineers avoided replicating traces on the NonStop signal midplane to support each type of fabric, and they avoided large numbers of signal pins for the interconnect module connectors. This simplifies the interconnect module connectors and uses midplane real estate efficiently. 8