Time to process is all relative to settings used all things otherwise equal. I believe both RipX and SpectraLayers are using the same Demucs network but they’re probably not both using the same prediction shifts and overlaps settings or even model size. Each prediction shift increase adds time to process and then much above .8 overlap settings will be exponentially time consuming. e.g. I can run the same song with 1 shift and 0.25 overlap and it’ll take 10 seconds. Change it to 20 shifts and .99 overlap and it’ll take all day, it doesn’t necessarily mean I will notice much difference in the result, but I would imaging RipX have chosen to use higher settings than SpectraLayers that’s all.