I love GTA IV and without putting spoilers in, I had to run the last mission with fraps on, limiting to 30fps because any higher it was impossible to complete. The game was a carbon copy of the console version, down to how it was meant to run frame wise. Rockstar didn't even bother giving an after thought on us PC gamers because they didn't even patch it.
Rant over and point is...Maybe these are the kind of games that just will not work. Lazy ass ports will need a miracle to get working and no matter what tool you use, it just ends up making it worserer.![]()
GTA:SA was hilarious if you disabled framerate control and had a fast PC+120+Hz you'd crater and die just jumping up and down on the spot as the falling distance calculation was tied to the number of frames that past and vsync factored in somewhere to

EDIT: I think they did different calculations for if vsync was on or not but assumed vsync was always 60Hz or less.