System information

Dell
PowerEdge M1000e Technical Guide 41
7 Midplane
Though hidden from view in an actively running system, the midplane is the focal point for all
connectivity within the Dell™ PowerEdge™ M1000e modular system. The midplane is a large printed
circuit board providing power distribution, fabric connectivity, and system management
infrastructure. Additionally it allows airflow paths for the front-to-back cooling system through
ventilation holes.
Figure 26. Midplane
As is requisite for fault-tolerant systems, the M1000e midplane is completely passive, with no hidden
stacking midplanes or interposers with active components. I/O fabrics and system management are
fully redundant from each hot-pluggable item. The system management Ethernet fabric is fully
redundant when two CMCs are installed, with two point-to-point connections from each server
module.
The midplane serves as transport for a patent-pending, time-division–multiplexed serial bus for
general purpose I/O reduction. This serial bus contributes greatly to the midplane’s I/O lane count
reduction, which is typically burdened with a significant I/O pin and routing channel count of largely
static or low-speed functions. For instance, all Fibre Channel I/O Passthrough module LED and SFP
status information is carried over this bus, which alone eliminates over one hundred point-to-point
connections that would otherwise be required. The time division multiplexed serial bus is fully
redundant, with health monitoring, separate links per CMC and error checking across all data.