A method (which can be computer implemented) for processing a plurality of adjacent rows of data units, using a plurality of parallel processors, given (i) a predetermined processing order, and (ii) a specified inter-row dependency structure, includes the steps of determining starting times for each individual one of the processors, and maintaining synchronization across the processors, while ensuring that the dependency structure is not violated. Not all the starting times are the same, and a sum of absolute differences between (i) starting times of any given processor, and (ii) that one of the processors having an earliest starting time, is minimized.