The computational cost of the generalised MSER methods is likely negligible compared to the cost of generating the data. However, computational cost may become a consideration when the algorithm is run repeatedly, for example if applied to individual λ states in alchemical free energy calculations. In general, the computational cost increases with increasing treatment of correlation, as more terms in the autocovariance sum must be evaluated. Hence, the N n 0 window method also has the advantage of speed over the initial sequence methods. In our current implementation (RED 0.1.1), we generally found the ratio of speeds to be ≈ 1 : 2 : 8 for the Uncorrelated, Window Size N n 0 , and all "Initial Sequence" methods, respectively on the "standard" time series of 10 4 points. However, this is highly dependent on the implementation.