Setting number of threads used in running a STARDIS simulation

When you run a STARDIS simulation, the yaml file determines how many threads are used. By default, it will only use 1 thread. The more threads you set a simulation to use, the more computing power the simulation will take advantage of for calculating line opacity and ray tracing steps (as both of these are parallelized in STARDIS). Setting n_threads to 0 will make the simulation use all available threads.

Here is a what a yaml file that has the STARDIS simulation use 3 threads will look like

stardis_config_version: 1.0
n_threads: 3 # <-----------  add your 'n_threads: <integer>' here
atom_data: kurucz_cd23_chianti_H_He.h5
model:
    ...

One reason you may want to consider increasing threads used is when computing spectra with large numbers (i.e. 10,000 or more) of wavelength points.