busy pdm server slow SolidWorks

some of my users are reporting that when the pdm server is experiencing heavy loads (large quantities of files being checked in) they are experiencing slow response from solidworks on their local computers. it was my understanding that when a file was opened from pdm you were accessing a local copy and that you only interacted with pdm when checking in/out or state changes.

why would server load effect models that are already open?

SolidworksSolidworks Pdm/enterprise Pdm