Runtimes of Gaussian and hyperfine fits. Results are shown for Gaussian fits to C¹⁸O (red lines) and ¹³CO (blue lines) spectra and for hyperfine fits to N₂H⁺ spectra (cyan lines). The CPU speeds are slightly below (i.e. faster) than the dotted line for 100 spectra per second. The GPU fits are in the range of 10⁵–10⁶ spectra per second. In the legend, 1G and 2G refer to fits with one or two Gaussian components, respectively. The timings correspond to the x view direction, but the runtimes are nearly identical for the other view directions.