As seen on Daemonnews, The Jem Report has a comparison of FreeBSD 5 on an AMD64 machine and a Pentium 4 machine. FreeBSD 5 performance is not directly comparable to DragonFly, but the architecture comparison is useful.
The prices classes of the two cpus compared are entierly different.
It would’ve been more fair to compare it with an amd fx-51 since they’re closer priced
DragonFly BSD Digest