Hi Johan,
Your wording is a little vague - I assumed that you had two ArchiCAD running, and were switching between them via the task bar/alt-tab/etc. That's the part that should have zero delay.
If you mean closing one empty file and opening another, then, yes, there will be a delay as the libraries for the new file are opened. If the libraries are on a server, the delay can be noticeable, but should not be extreme Does your network work quickly otherwise? If you simply copy the shared library from the network in Windows Explorer to your local machine, is there a huge delay?
ArchiCAD does read various local files, depending on your network setup. Preferences, work environment, etc will be local. In your Work Environment, you can see the paths to where AC is looking for some other things...
Is your WIBU key on a server, or in your local machine? Finding/checking the key might be taking some time; I'm pretty sure that there are some tips in these forums about adjusting the WIBU network setup to find the key server more quickly. Your firewall can also be an issue in this case. See:
http://www.archicadwiki.com/TechNotes/WIBU_network_key_is_not_accessible_on_Windows_XP_SP2?highlight...
Karl
One of the forum moderators
AC 28 USA and earlier • macOS Sonoma 14.7.1, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB