OrientDB official site says:
On common hardware stores up to 150.000 documents per second, 10 billions of documents per day. Big Graphs are loaded in fe
You can achieve that by using 'Flat Database' and orientdb as an embedded library in java see more explained here http://code.google.com/p/orient/wiki/JavaAPI
what you use is server mode and it sends many requests to orientdb server, judging by your benchmark you got ~10 000 inserts per seconds which is not bad, e.g I think 10 000 requests/s is very good performance for any webserver (and orientdb server actually is a webserver and you can query it through http, but I think java is using binary mode)