I saw this blog entry from freebase: http://blog.freebase.com/2008/04/09/a-brief-tour-of-graphd/
Quote: "We recently demonstrated sustained throughput of about 200,000 simple queries per minute on a single AMD64 core. Simple queries are things like "show me all people who are authors with names containing 'herman'" "
Maybe something worth looking into?
Cheers, Magnus