RTC runs very slow, could you please help me this issue?

It’s take a long time ( nearly 20 minute) to start RTC. And more terrible when create, delete or modify something.Although I reintalled NAV, such issue still happen. Could you please meet or have the solution for this?!

PS: when starting, the process bar is shown:“A connection to the server has been established. Preparing your workspace…”

Thanks all, I got the issue and how to solve it. Because of joining domain so it make performance down. Thanks!