The wavefront array processor is a systolic structure that implements the principle of data flow control. The paper is devoted to methods for calculating the performance of an acyclic wavefront array processor. Data processing is gradient if at each moment of time all operations for which their input data are ready should be performed. It has been established that gradient processing has minimal time. A graph with weighted vertices is constructed, the maximum path length is equal to the processing time of a given amount of data for an acyclic wavefront array processor. An algorithm for the calculation the processing time of a given amount of data by this processor is proposed. The results can be used to calculate performance in the development of processors, co-processors, multi-threaded cloud applications implementing business processes, as well as non-linear pipelines associated with mass production.