Soap Server - performance issue (might be SQLite related)
Do you use a FQDN for the server's address? In that case it might actually be DNS-related. You might also want to try everything on a real system and not on a virtual host, as you will not have much control over what the physical system is actually doing.
Secondly, I would recommend installing xdebug and use kcachegrind or wincachegrind, which will give you a much more detailled view of what your system is doing.
Thirdly, you may log slow queries by utilizing PostgreSQLs pg_stat_statements().