Hi Quyet,
You are right, Trimble Connect Desktop does sync data to and from server.
Syncing of lots of project may take quite some time. It should get better if you wait for a while, so that Trimble Connect Desktop has synced everything.
Do you see the slowness on all projects? If just on few project, could you invite me (marko.myllymaa _@- trimble.com) to such project?
You can set how often Trimble Connect Desktop syncs the project data by editing editing TrimbleConnect.exe.config file (located in C:\Program Files\Trimble\Trimble Connect). In that file you can see line:
<add key="EntitySyncFrequencyInMinutes" value="2" />
Just edit the value to be what you want.
Best regards,
Marko Myllymaa