In this paper, the global power conversion efficiency is improved for a fault-tolerant drive architecture.The fault-tolerant architecture is obtained by combination of a 3-phase open-end winding machine anda 3H-bridge inverter. This combination offers more degrees of freedom for the control strategy than aclassical 3-leg inverter. This paper demonstrates that the additional degree of freedom of this powersystem can be exploited for efficiency optimization purposes in normal operation mode. In the presentwork, the retained optimization criteria is the minimization of the drive losses which is a critical issue.In addition, to fulfill the torque demand, this leads to a constrained optimization problem which can beanalytically solved using the Lagrange multipliers method. Besides, as each motor phase can be drivenindependently, the resolutions for three strategies, i.e. for three, two or one-phase simultaneous con-duction of the inverter, provide three different optimal current waveforms. This is the key point of theproposed efficiency-optimal power partitioning for improved partial load efficiency of electric drives.Finally, on a test bench, the real-time tracking of the mentioned current waveforms is successfully testedand power measurements confirm the possibility of using the three different control strategies to realizean efficiency optimum phase-shedding strategy.