In an aspect, a wireless device with a plurality of transmitter chains that can be selectively used to transmit a beam-formed signal determines a targeted receive power for the beam-formed signal, with respect to a target receiving device. The wireless device selects a number of the plurality of transmitter chains for forming the beam-formed signal, based on the targeted receive power and based on an estimated power consumption for each of the plurality of transmitter chains. The selection is performed so as to minimize a total power consumption, given the estimated power consumptions. The wireless device transmits a beam-formed signal, using the selected number of the plurality of transmitter chains.