#1: Plugins your using would help.
#2: Specification of your machine (CPU , RAM , Graphics, etc).
#3: Read the FAQ's at the top of this forum.
#4: The PS2 is an extremely complex machine, so if you don't have the BEST machine money can buy out there (and even then you won't get top speeds), you'll get no where near decent FPS.
#5: With the current beta I can achive a FPS range of 22-71 FPS in any bios, now compare your spec to mine and go figure