Kernel driver ibmaem

This driver talks to the IBM Systems Director Active Energy Manager, known henceforth as AEM.

Supported systems:

  • Any recent IBM System X server with AEM support.

    This includes the x3350, x3550, x3650, x3655, x3755, x3850 M2, x3950 M2, and certain HC10/HS2x/LS2x/QS2x blades.

    The IPMI host interface driver (“ipmi-si”) needs to be loaded for this driver to do anything.

    Prefix: ‘ibmaem’

    Datasheet: Not available

Author: Darrick J. Wong


This driver implements sensor reading support for the energy and power meters available on various IBM System X hardware through the BMC. All sensor banks will be exported as platform devices; this driver can talk to both v1 and v2 interfaces. This driver is completely separate from the older ibmpex driver.

The v1 AEM interface has a simple set of features to monitor energy use. There is a register that displays an estimate of raw energy consumption since the last BMC reset, and a power sensor that returns average power use over a configurable interval.

The v2 AEM interface is a bit more sophisticated, being able to present a wider range of energy and power use registers, the power cap as set by the AEM software, and temperature sensors.

Special Features

The “power_cap” value displays the current system power cap, as set by the AEM software. Setting the power cap from the host is not currently supported.