OK, i found out that the 1950x is not the problem, but the encoders ( like handbrake, vidcoder and so on) are.
They all seem to be optimized for 6 / max 8 cores.
I did some testings on weekend und will do some more and post the results here in the next days.
Maybe this can help someone, who things that there is a driver problem or something like that. No, its not
Here are a few results:
The episode, which I encoded is still the same and the configuration of vidcoder too.
3930k (my old cpu) with 12t needs 1h33m
1950x (my new cpu) with 32t needs 0h54m
Thats to slow, so I created a VM with w10, running on my 1950x with w10.
VM (1950x) with 6t needs 1h37m
VM (1950x) with 8t needs 1h13m (+2t = +32%)
VM (1950x) with 12t needs 1h03m (+4t = +15%)
So it is better, to use only (max) 8 threads for a encoder like vidcoder or handbrake.
Handbrake offers a command line interface, so it is possible to run a job with one long commandline limited maybe to 6 threads.
Than start a second commandline with another encoding .. and so on.
Maybe its possible to split a encoding into 3 parts, so first cl starts encoding from 0m to 30m, the second from 30m to 60m, but I dont know, how to merge theese parts again.