Advice for Management Software

Hi everyone! I’m new on Rails and coming from PHP world (Symfony)

I want to do a management application. Most of things that I need are
list, search… so an admin interface is ok for what I need. I have
RailsAdmin and has great functionality.

But my question is about performance, because my application will have
concurrent users. So, will using an admin interface will drop down the
performance (memory and speed)?

It would be better to make things by hand or with the admin?