Time required to search structure neighbors depends on the level of similarity between query structure and known structures in PDB, size of the structure and load on the server and may vary from 5 minutes to 10 hours.
Option "Use structure representatives" (default) is advised for faster search. In this case structure neighbors for query structure will be derived from representative
structure if it exists for a given query structure. Otherwise, full search will be performed. In both cases search is performed on a set of representative structures and then all other structure neighbors associated with representatives are added.