With reference to the manual entry, can you tell me what, these days, qualifies as a high CPU count system and suggest a maximum numbers of cores to select for using "some plugins". It would also be useful to know which plugins "some plugins" refers to.
I am using an i7 8700k, up to 4.7GHz hex core processor (6 cores 12 threads), should that be throttled?
The more threads you use, the more setup has to be done. So if you have a small task, the program can waste time setting up the threads rather than just doing the job. SMP count can be set up in Settings->Preferences, Performance tab. FFmpeg cuts out at 15 for the number of threads to create. Here is what gg uses on his ryzen (which is crazy with 128 cpus so is the case where too many threads will slow down the work).
width X height / 0x80000+1 number of cpus for slicers
OR approximately 1/2 megapixel gets a cpu (per task)
Plugins using threads can be seen by typing this in a window from {your cinelerra path}/cinelerra/plugins:
grep -Il LoadClient */*.C 2> /dev/null
Plugins use threads and some gui's use threads so anything with a capital letter T (followed by thread) uses threads.
And anything that uses "OverlayFrame" and "LoadClient". Also anything that uses "transfer" follows the megapixel setup shown above.
Short answer: if you have less than 15 cpus you should probably just set SMP count to the number of cpus you have.
