1. A method of producing a benchmark application for testing input and output (I/O) settings of a computer application, the method comprising: compiling trace data relating to operations to be executed by the computer application; grouping the trace data into one or more phases, based on different stages in an execution of the computer application to which the operations relate; identifying patterns in the trace data and comparing the patterns; producing simplified trace data in which trace data having similar patterns are combined; and outputting a benchmark application which includes the simplified trace data and information indicating where the trace data have been combined.