There is today consensus on the fact that optical interconnects can relieve bandwidth density concerns at integrated circuit boundaries. However, when it comes to the extension of this emerging interconnect technology to on-chip communication as well, such consensus seems to fall apart. The main reason consists of a fundamental lack of compelling cases proving the superior performance and/or energy properties yielded by devices of practical interest, when re-architected around a photonically-integrated communication fabric. This paper takes its steps from the consideration that manycore computing platforms are gaining momentum in the high-end embedded computing domain in the form of general-purpose programmable accelerators. Hence, the performance and energy implications when augmenting these devices with optical interconnect technology are derived by means of an accurate benchmarking framework against an aggressively optimized electrical counterpart