HPC FAQ: Difference between revisions
Content deleted Content added
No edit summary |
|||
Line 55:
* Be more thorough in reviewing the model results. Although this is best practice for any modelling, it is paramount for unconditionally stable solvers like HPC that thorough checks of the model’s flow patterns, performance at boundaries and links is carried out.
* The CME%, which is an excellent indicator that the Classic 2D solver is numerically converging, is not generally of use for HPC, which is volume conserving and effectively 0% subject to numerical precision. Non-zero whole of model CME% for HPC 1D/2D linked models is usually an indication of either the 1D and 2D adaptive timesteps being significantly different, or a poorly configured 1D/2D link.
= Why is my model using 2020 HPC twice as slow as 2018 HPC?=
The change in runtime can be due to different timestepping applied with the new default - mesh size insensitive turbulence model - Wu instead of Smagorinsky. Not all HPC models will show an increase in runtime when changing from the 2018 to the 2020 release - models that are controlled by the wave celerity or velocity control numbers and not the diffusion control number are likely to be similar in runtime. Some models will be even faster with the last 2020 release due to other improvements.
| |||