I can vouch for Strange 100%, my Athlon XP system does exactly the same as his fps wise. Mines a 2500+ @ 2.23Ghz, compared to his 1700+ @ 2.3GHz (I think), the difference is negliable and my hardware setup apart from the CPU & mobo is near identical
If you go into some heavy fighting it can drop by 10 fps to about ~60, sometimes a little lower @ 55. There are a few levels that cause it to go at about 45fps in heavy fighting, although I cant remember the name off hand. (Possibly the Astaroth/Lizardman levels)
Best levels to speed test are Chaos, Proving Grounds and the Water Raft one you fight Yoshimitsu in. Playing in Practice, Versus or Arcade dont appear to make any difference, not that I can tell anyway.
~P