Estimating Runtimes

This page provides information on estimating runtimes for TUFLOW, specifically focusing on 2D computational time for TUFLOW Classic (not TUFLOW HPC). For details on how TUFLOW HPC runtimes differ from TUFLOW Classic, refer to How much faster is TUFLOW HPC compared to Classic?

This estimation also does not account for 1D computational time. In the majority of cases the 2D computational load is far greater than the 1D, and as such, is typically the dominant factor that influences the overall simulation runtime. The proportion of simulation time spent on the 1D and 2D hydraulic calculations, and also other tasks, can be reviewed via the _run_stats.txt log file.

The spreadsheets linked below can be used to estimate TUFLOW simulation times based on the cell size, catchment area and simulation time (i.e. event duration). The runtime depends on a number of factors such as the speed of the CPU and also the fraction of the model that is wet. The more wet cells the more calculations that are required and therefore the slower the simulation.

The timestep used in a TUFLOW simulation is dependent on a variety of factors such as the steepness of the topography, the depth of water and the velocities encountered, in the spreadsheet a typical range of timesteps is calculated based on the cell size. For a TUFLOW model running in metric, the timestep (in seconds) is typically between 1/5 to 1/2 of the cell size (in metres). For example a 10m model will typically have a timestep between 2 and 5 seconds. Therefore, two estimates of runtime are provided in the spreadsheet one based on the smaller and one based on the larger timestep.

The second sheet in the attached excel files is titled Cell_Calcs_per_second and gives a guide to estimating this on your machine.

Given the inexact nature of the calculations these are estimates only, but do give a reasonable indication of runtime!

File:Estimate runtimes metric 001.xlsx
File:Estimate runtimes Imperial 001.xlsx