In the paper we compare two approaches of intentional introduction of inter-symbol interference (ISI) into single-carrier signal to improve its bandwidth efficiency. The first approach is “faster-than-Nyquist” signaling (FTN) with infinite rrc-pulses. The second approach is generation of multicomponent signals (MCS) utilizing optimal finite pulses. In the optimization problem, we used a criterion of minimal bandwidth comprising 99 % of signal power. The maximal level of ISI and peak-to-average power ratio were used as additional constraints. The comparison of optimal MCS and FTN is given in the bandwidth and energy consumptions plane for the fixed computational complexity of the receiver. In addition, we considered modified energy consumptions taking values of PAPR into account. It is shown that optimal MCS provide lower consumptions with respect to FTN with rrc-pulses.