Power Monitoring

On-board Power Measurement Tools

For Bluefield cards, we think we should be using IPMI to measure power (details forthcoming).

External Power Measurement Tools

These tools use a physical measurement device like a BeagleBoard along with a custom current measurement harness to measure the dynamic current of an attached device. Generally this current is then multiplied by the supply voltage to get the power usage of the device. As an example, a Jetson TX2 board might be supplied by a 12 Volt supply input - if we can measure that that input current is 1.32 Amps we can then determine that the current instantaneous power usage is 15.84 Watts.

There are several different devices that have been proposed for measuring power externally shown in the table below along with links to papers for each device. PowerInsight was productized by Penguin Computing and WattProf has been produced by RNET.

Sampling Frequencies

This specifies how fast a particular device can sample input currents and voltages. While there is also potentially some latency (e.g., data being reported via USB) in reporting this to the host, this indicates how granular the results are for instantaneous power usage. This table provides a rough estimate of current power monitoring solutions we are aware of.

Device Type Sampling Frequency (KHz)
PowerMon 2 External 1 per channel with 3 channels
PowerInsight External 1
WattProf External 1-10
Intel S10 FPGAs On-board 10-1000
NVIDIA GPU (using NVML) On-board 1-3