Optimal transceivers that minimize the transmission power for a given probability of error and transmission bit rate will be evaluated for ADSL applications. We will compare the performance of the optimal DMT systems to that of DFT based DMT systems. The experiments show that the optimal DMT system usually has a gain of 3 dB or more over that of DFT based system. For comparable performances, the optimal DMT requires a smaller number of subchannels and hence has a smaller system delay.