Investigated was the transmission over step index POF that is 50m/100m long with a red DVD laser as a source and a Si p-i-n commercial photo-detector. The maximum bit rates of three modulation formats: PAM, CAP and DMT were sought. Their constellation sizes and symbol rates were varied in order to maximize FEC limited throughputs for each modulation whereas the laser operating point and relevant optical powers were maintained constant for all the modulations. The maximum throughputs were similar for PAM and CAP, namely 3.3/2Gbit/s for PAM, and 3.15/2.1 for CAP for 50/100m fiber, respectively. The bit rates for DMT were 2.65/1.65Gbit/s for the respective lengths of the fiber. We attribute the inferior performance of DMT to its high value of peak to average power ratio.