Stills Export speed varying so much

Usually when I export stills for a 5-10 minute video segment, it takes maybe 45 minutes. Sometimes it slows down to a crawl independent on whatever else is happening on my computer, like the fans dont get louder, nothing. It seems like the amount of time that it takes is super inconsistent, and once it gets slow it stays slow for multiple jobs. Like I’m exporting stills now, and it says 2.45 hours for 3 minutes?!? Did anyone else know how come this is happening… It would be cool to understand what made it slow down so exponentially.

Which filter are you using? hqnd3d does need much power, the stabilization needs much power
Slideshows (stills) are exported much faster than anything else.

When you export stills, it might be good to have the still image in exactly the same resolution than the video output format.
Sadly programs like darktable don’t do this, even when you define the export resolution correctly from darktable!

it varies based on how many filters, transitions … and your computer capacity … how many memory avaliable to proceed … if uses SSD type and etc !