The advent of optical amplifiers have revolutionized optical communications, facilitating (Wavelength Division Multiplexed) WDM systems and leading to an explosion in bandwidth and data rates. But long amplified links degrades the optical Signal to Noise Ratio (SNR) with each stage of amplification due to the addition of Amplified Spontaneous Emission (ASE). This is overcome by using regenerators which does the Optical-Electrical and back to Optical (OEO) conversion to detect the signal and regenerating it anew thereby removing all the noise and hence restoring the SNR. But this electrical conversion introduces delays and prohibitively increases the cost of the link. A potential solution for this is the use of all optical regenerators, which does the amplification and reshaping in the optical domain itself. This paper undertakes a BER analysis proving the unconditional superiority of regenerators over repeaters for given link parameters. It also demonstrates the better power savings and extra reach of all optical regenerators. Further, a few approximations are used to represent the Q function analytically and the corresponding expressions are used for comparing the performance of repeaters and regenerators. © 2020 IEEE.