Thanks for your reply.
I have done some further tests:
The performance problem I have only when I add many pictures for a timelaps video.
I will add about 500 - 700 pictures to the Media Room and then to timeline, after that I will remove the pictures from the Media Room because of the 2.500 media limits. Then I will add again ~ 500 pictures.
During this I can see that PD is using always 25 % CPU.
But I think the main problem is not the CPU, the problems are the file handles which are used from PD process.
In the task manager I can see, that PD will get problems, when there are more then ~ 3.000 handles acitve.
The process is not responding for a while and the file handles increase and increase to more then 10.000 handles.
There is one file handle for all the importes pictures and it take a long time, that they will be closed.
If I save the project and close PD and then reopen this project it will take also a long time to load it.
I know, if you produce videos you normaly never have so many files.
But is this a normal or are there any chance to improve this?
A little bit strange for me is, that I can't see the file access on the disk in the ressource monitor. So the file handles are all in the memory? The memory will increase in this time, but not to the system limit. (about 3-4 GB from 8 GB are in use)
Thanks again
Martin