HP BladeSystem c-Class architecture Technology brief, 4th edition

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Signal midplane provides reliability
To provide high reliability, we designed the NonStop signal midplane as a completely passive board.
It has no active components along the high-speed signal paths. The PCB consists primarily of traces
and connectors. While there are a few components on the PCB, they are limited to passive devices
that are unlikely to fail. The only active device is an EEPROM (Electrically Erasable Programmable
Read-Only Memory) utility, which the Onboard Administrator uses to get information such as the
midplane serial number. If this device fails, it does not affect the NonStop signal midplane. The
solutions include the HP NonStop S-series, core networking switches from HP Networking, Cisco, and
Juniper Networks, and core SAN switches from Brocade and Cisco.
Separate power backplane
The PCB power backplane is separate from the NonStop signal midplane. This design improves the
signal midplane by reducing its PCB thickness, reducing electrical noise from the power components
that would affect high-speed signals, and improving the thermal characteristics. These design choices
result in reduced cost, improved performance, and improved reliability.
Power backplane scalability and reliability
To minimize losses while distributing power, the power backplane has solid copper plates and
integrated power delivery pins (Figure 12). Solid copper plates reduce voltage drops, produce high
current density, and provide high reliability.
Figure 12: c-Class power backplane and the power delivery pins
Power and cooling architecture with HP Thermal Logic
With the BladeSystem c-Class architecture, HP engineers consolidated power and cooling resources
to manage them efficiently within an enclosure. Every level of the architecture contains Thermal Logic
technologies: processors, server blades, Active Cool fans, and the c-Class enclosure itself. Thermal
Logic, which refers to the mechanical features and control capabilities throughout the design, gives