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# Calculating Power Requirements for a QFX3008-I Interconnect Device

Use the information in this topic to calculate power consumption, system thermal output, and number of power supplies required for different QFX3008-I Interconnect device configurations.

Before you begin these calculations:

## Power Consumption of Different QFX3008-I Interconnect Device Configurations

• To calculate the maximum system power consumption for a QFX3008-I Interconnect device with one 16-port QSFP+ front card installed:

Add the individual power requirements of all components in the chassis configuration. See Power Requirements for a QFX3008-I Interconnect Device.

Thus, power consumption = Power requirements of: (Chassis) + 1 (16-port QSFP+ front card)

= 4500 W + 240 W

= 4740 W

• To calculate the maximum system power consumption for a QFX3008-I Interconnect device with eight 16-port QSFP+ front cards installed:

Add the individual power requirements of all components in the chassis configuration. See Power Requirements for a QFX3008-I Interconnect Device.

Thus, power consumption = Power requirements of: (Chassis) + 8 (16-port QSFP+ front card)

= 4500 W + 8 (240 W)

= 4500 W + 1920 W

= 6420 W

## System Thermal Output for Different QFX3008-I Interconnect Device Configurations

To calculate the system thermal output in British thermal units (BTU) per hour for your device configuration, multiply the maximum system power consumption of the switch by 3.41.

To calculate the system thermal output for a fully loaded QFX3008-I Interconnect device:

1. Compute the maximum system power consumption of a fully loaded configuration. See maximum system power consumption for a fully loaded configuration device in Power Consumption of Different QFX3008-I Interconnect Device Configurations.
2. Multiply the maximum system power consumption by 3.41

= 6420 W x 3.41

System thermal output for a fully loaded switch configuration = 21,892 BTU/hr

Note

Using the maximum system power consumption values to calculate the system thermal output often results in overprovisioning the cooling systems. Typical power consumption is about one-third lower than these calculated values.