For the optimization of the drive train efficiency, a trade-off between inverter and machine losses is of importance. The inverter's switching frequency and modulation technique influence these losses. In this paper the power loss characteristics of a 70 kW interior permanent magnet synchronous machine are analyzed for different switching frequencies and modulation techniques. Furthermore the machine losses are opposed to the losses of a three phase two-level voltage source inverter. Finally the benefit through the optimization process is shown for several operating points and utilized on a driving cycle. The results of the paper are derived from measurements on a test bench.