[johnmeyer]

I assume the breakthrough increase in speed was from the avstp.dll addition since it didn't appear that he was getting any MT even with the hard-wired threads(4) statement. I also assume that the SetMemoryMax increase had no impact on speed since, in my experience, memory allocation is entirely a setting for stability, not performance.

Feel free to correct me, if these assumptions are incorrect.

BTW, the next thing to try is to change the threads setting to find the "sweet spot." This can sometimes be counter-intuitive, given the strange way in which multi-threading works in various flavors of AVISynth. The only way I've been able to tune this is to run the script for 30-60 seconds, and then note where the fps results end up after that time (the initial fps can be quite misleading because of caching from a previous run). Then, I change threads up or down, and repeat.

I only have eight cores, and with my system, with most scripts (including this film restoration script), threads=8 is almost always really slow and unstable. Based on experience, I usually start my tuning with threads=4 (i.e., half of my cores), and work up or down from there. For many of my scripts, I get the best performance, with stability, with threads=5, but I've had to go as low as 3 and sometimes have gotten as high as 7, so I have learned that I must always do these brief tests.