Calculations of Power Consumption of Cisco Devices!

[Mohit Chauhan]

Hi,

I am trying to calculate power requirements for a new rack going with some Cisco devices. Now when I was looking at the data sheet specs of the devices, they show two parameters which I was looking at and wasn't sure which one to use to calculate the power requirement for the rack.

One parameter is "Power Supply Rated Maximum"

Second parameter is "Measured 100% Throughput Power Consumption"

Which would be the best option/way to calculate power requirement for the devices?

Thanks!

[Marvin Rhoads · Accepted solution]

While the second parameter is what you can expect the unit to draw, we typically design power feeds to match the first parameter.

The thought is that in the event of a power interruption, all devices in a rack may power on at once. During that process, many will surge beyond their steady state use levels to something closer to their theoretical maximum rating. If you haven't provisioned that much, you may end up tripping breakers at the time you can least afford it. 

[Mohit Chauhan]

Thanks Marvin. This was very helpful.