One of the most common problems in God of War 2 PCSX2 is slow motion gameplay during cutscenes, boss fights, and heavy combat scenes. During testing, the issue was usually caused by incorrect speedhack settings rather than weak hardware.
A lot of older PCSX2 guides still recommend aggressive tweaks for extra FPS, but modern PCSX2 2.6 and newer builds already handle optimization much better by default. In many cases, those old tweaks actually make the game slower or unstable.
FPS drops are usually most noticeable during the Colossus of Rhodes battle, large enemy groups, and fire heavy combat scenes.