Jan Lentfer performed some Postgres benchmarks on DragonFly. It’s elaborate enough that it’s in the form of a PDF attached to the message I’ve linked. There’s some additional variations that haven’t been tried yet.
Vigorous file system activity seemed to lower performance in the long term on Hammer, which is certainly something to investigate. More testing please!
New mail with new stats is in the list:
http://leaf.dragonflybsd.org/mailarchive/users/2009-10/msg00131.html