Module Power Consumption And System Power Consumption; Heat Dissipation - HP FlexFabric 7900 Series Installation Manual

Module power consumption and system power consumption

Card power consumption
The power consumption of the card depends on the card state.
the LSV1QGS12SA1.
Static power consumption—Power consumed by the card when the card is running but all ports on
•
the card are down and no transceiver modules are installed on the fiber ports of the card.
Dynamic power consumption—Power consumed by the card when the card is fully configured and
•
sends broadcasts at wire speed.
Table 10 Card power consumption
Model
LSV1QGS12SA1
Fan tray power consumption
The switch uses fans with the automatic speed adjustment function. The fan speed is automatically
adjusted based on the heat dissipation condition of the switch. The power consumed by a fan tray
depends on the fan speed.
Table 11 Fan tray power consumption
Model
HP 7904 fan tray
System power consumption
The system power consumption of the switch depends on the type and number of the cards and fan trays.
Minimum system power consumption—Static power consumption of all cards + Minimum power
•
consumption of all fan trays.
For example, for an HP 7904 switch that has four LSV1QGS12SA1 LPUs and two fan trays, the
minimum system power consumption is: 4 × 160 + 2 × 18 = 676 W.
Maximum system power consumption—Dynamic power consumption of all cards + Maximum
•
power consumption of all fan trays.
For example, for an HP 7904 switch that has four LSV1QGS12SA1 LPUs and two fan trays, the
maximum system power consumption is: 4 × 230 + 2 × 130 = 1180 W.

Heat dissipation

Heat dissipation is measured in BTU/h, and 1 W equals 3.4121 BTU/h.
The heat dissipation of a switch depends on its power consumption. To calculate heat dissipation of the
switch, assume 90% power consumption is converted to heat, and the efficiency of the power supply is
90%. Heat dissipation/hour of the switch is 0.9 × (total power consumption of the cards plus power
consumption of the fan tray)/0.9 × 3.4121.
For the power consumption of the cards and fan trays of the HP FlexFabric 7900 switch series, see
"Module power consumption and system power
Static power consumption
160 W
Minimum power consumption
18 W (40% speed)
consumption."
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Table 10 lists the power consumption for
Dynamic power consumption
230 W
Maximum power consumption
130 W(100% speed)