Why python-2.7.3 is much slower on BSD than on Ubuntu on the same HW?

[Yuri]

I am looking at one testcase from this meld PR 
https://bugzilla.gnome.org/show_bug.cgi?id=657763 .
The same file comparison on the host amd64 9.0 works in 14 secs, but in 
VBox guest VM Ubuntu on the same host it runs in 4.3 sec, all user time.

python on both OS has the same version 2.7.3, and meld is a bit 
different: on 1.6.0 and 1.5.3 but this shouldn't matter since this has 
been this way for a long time.

Why python app on FreeBSD works so much slower?

Yuri