A 64×10 Gb/s nonreturn-to-zero wavelength division multiplexing system (WDM) for 100 GHz spaced with an efficient high gain optical amplifier is demonstrated using a fiber Raman amplifier (FRA). The WDM signals are propagated through a span comprising a single-mode fiber (96 km), a dispersion compensated fiber (16 km), and a Raman fiber (10 km). The FRA is pumped by only two pump wavelengths in the counterpropagating mode. The performance of this system is analyzed for different placements of Raman amplifier in the span, i.e., as pre, post, and both (pre and post), and it is concluded theoretically that the post configuration of the Raman amplifier is the best choice for the WDM system. With an input signal power of 0 dBm, a gain flatness of 4.4 dB with quality >11 dB is obtained across the frequency range of 188.35 to 194.65 THz without using any hybrid configuration or gain equalization technique for a transmission distance of 424 km. We present a comprehensive comparison of the performance of the WDM system by analyzing the results obtained from different configurations for different spans of fiber length.