A method for optimizing the parallel processing of data on a hardware platform, the hardware platform comprising: - at least one computing unit comprising a plurality of processing units able to execute a plurality of work items in parallel in a processing space, the processing space being a space in which a same sequence of operations is carried out on all of the data, the processing space being able to be broken down into processing subsets, each subset performing the same processing on a data subset, the method being characterized in that the method comprises the following steps: - obtaining a maximum number of work items executable in parallel by a computing unit of the hardware platform, - determining sizes of the data subsets of the processing space through a same sequence of operations to obtain determined sizes, - optimizing the size of at least one data subset of the processing space, the optimization comprising a step for: - selecting, for at least one considered subset, at least one integer number strictly greater than the determined size and multiple numbers smaller than the determined size of the considered subset, the number(s) smaller than the determined size of the considered subset preferably being 2, 4 or 8, - generating, for each subset considered in the selection step, a computation subset having, as size, the integer selected from the subset and comprising all of the data of the considered subset, the computing subset replacing the data subset considered in the processing space, to obtain a new processing space, the optimization being implemented so as to obtain an improved execution performance measurement for the new processing space relative to the execution performance measurement obtained for the processing space in which the considered data subset has the determined size according to at least one chosen criterion, the measurement being associated with the execution of a program including program code instructions implementing a processing partition corresponding to the partitioning of the considered processing space into data subsets, and assigning at least one executable work item, able to execute said sequence of operations, to each data subset, the total number of executable items per data subset being less than or equal to said maximum number of items. - at least one computing unit comprising a plurality of processing units able to execute a plurality of work items in parallel in a processing space, the processing space being a space in which a same sequence of operations is carried out on all of the data, the processing space being able to be broken down into processing subsets, each subset performing the same processing on a data subset, - obtaining a maximum number of work items executable in parallel by a computing unit of the hardware platform, - determining sizes of the data subsets of the processing space through a same sequence of operations to obtain determined sizes, - optimizing the size of at least one data subset of the processing space, the optimization comprising a step for: - selecting, for at least one considered subset, at least one integer number strictly greater than the determined size and multiple numbers smaller than the determined size of the considered subset, the number(s) smaller than the determined size of the considered subset preferably being 2, 4 or 8, - generating, for each subset considered in the selection step, a computation subset having, as size, the integer selected from the subset and comprising all of the data of the considered subset, the computing subset replacing the data subset considered in the processing space, to obtain a new processing space, the optimization being implemented so as to obtain an improved execution performance measurement for the new processing space relative to the execution performance measurement obtained for the processing space in which the considered data subset has the determined size according to at least one chosen criterion, the measurement being associated with the execution of a program including program code instructions implementing a processing partition corresponding to the partitioning of the considered processing space into data subsets, and assigning at least one executable work item, able to execute said sequence of operations, to each data subset, the total number of executable items per data subset being less than or equal to said maximum number of items. - selecting, for at least one considered subset, at least one integer number strictly greater than the determined size and multiple numbers smaller than the determined size of the considered subset, the number(s) smaller than the determined size of the considered subset preferably being 2, 4 or 8, - generating, for each subset considered in the selection step, a computation subset having, as size, the integer selected from the subset and comprising all of the data of the considered subset, the computing subset replacing the data subset considered in the processing space, to obtain a new processing space,