try to change gs and enable/disable hacks
You can try the playground version 1.0.0395. You can safely enable all of the speed hacks there. The game runs really well with very impressive graphics and very good sound (althouth sound in ingame movies is often out of sync). The intro can be configured to run flawlessly! Unfortunately, the speed without VU skipping is only half of what it has to be - about 30 fps in most situations in arcade mode. It is faster in conquest, however. Whatever the case, I find the game truly enjoyable despite some limitations. My system specs are E8500 (3.16 GHz), 2 GB of ram, 8800 GTS 512MB. Good luck!