Avoid the overhead of having the default <select> in Django Admin with all the related instances (ForeignKey or ManyToMany)...

Avoid the overhead of having the default <select> in Django Admin with all the related instances (ForeignKey or ManyToMany) just listing them in ModelAdmin.raw_id_fields. I've just done it and my admin change pages are being loaded up to 10x faster, avoiding a lot of request timed out error.