Clearing cache didn't improve anything?
Welcome to CD PROJEKT RED Technical Support! Here you will find help regarding our games and services, as well as answers to frequently asked questions.
support.cdprojektred.com
For performance issues, here's the support article from CDPR:
Welcome to CD PROJEKT RED Technical Support! Here you will find help regarding our games and services, as well as answers to frequently asked questions.
support.cdprojektred.com
You can contact them by clicking on "contact us"
That being said, if RT is on it might be better to disable it to improve performance.