ASPECT has a lot of postprocessing
capabilities, from generating graphical output to computing average
temperatures or temperature fluxes. To see what all is possible, take a look
List of postprocessors parameter that can be set in the input file,
Many of these postprocessors take a non-negligible amount of time. How much they collectively use can be inferred from the timing report ASPECT prints periodically among its output, see for example the output shown in Convection in a 2d box. So, if your computations take too long, consider limiting which postprocessors you run to those you really need. Some postprocessors - for example those that generate graphical output, see Subsection: Postprocess / Visualization - also allow you to run them only once every once in a while, rather than at every time step.