Relaxation-based techniques for the transient analysis of large-scale integrated circuits are promising candidates for a new generation of circuit simulators. The present note investigates the convergence of the discretized waveform relaxation. It is demonstrated that a SOR technique has the potential of beeing significantly faster than the conventional waveform relaxation Gauss-Seidel method. The determination of the optimal relaxation parameter is decisive and is discussed for the case of a general linear model problem.