Hi Carsten, JPEG2000-encoded video frames come back from the encoding threads (either local to the machine or over a network) at different times. They must be written out to disk in order so they have to be queued up before this happens. There's a maximum number of JPEG2000 frames that DoM will queue up in memory before it gives up and starts pushing to a temporary disk buffer. That maximum number is what this option controls. It's a trade-off between memory usage and encoding speed. DoM tries to guess a good value but if you have lots of cores and a reasonable amount of memory you might want to increase the maximum number of frames to store per thread as it may increase overall encoding speed. Cheers, Carl On Sun, 22 Oct 2017, Carsten Kurz via DCPomatic wrote: