PCGH (http://www.pcgameshardware.com/aid,685997/Street-Fighter-IV-PC-explained-in-detail/News/) asked the game's developer about the technical features used in SF4.
4Gamer (http://www.4gamer.net/games/049/G004954/20090612078/) provides the benchmark (http://file.4gamer.net/demo/StreetFighterIV_Benchmark.zip).
Unsurprisingly a beat-'em-up underchallenges contemporary GPUs.
minimum settings: 585 fps
default settings: 183 fps
maximum settings: 39 fps