when i compress some sound file using installed lame (in
/usr/pkg/bin/lame) build from pkgsrc (lame-3.87, netbsd-1.5.1) i've got
such times
205.08 real 200.39 user 1.51 system

when did the same but with /usr/src/pkgsrc/audio/lame/work/lame3.87/lame
(which is after strip byte-to-byte the same as /usr/pkg/bin/lame) i've got

222.28 real 218.31 user 1.51 system

result is repeatable, no other tasks were going.

could someone explain it or should i believe in magic?