I have done some more tests and found some interesting case:
When running demo "Cylindric Scroll (Demo) by Concept" ->
http://janeway.exotica.org.uk/release.php?id=6403
The "sse2_speed" version is the fastest one (86-88% in task manager) and "sse2_speed_fastFP" is the slowest one (88->90% in task manager) !!!