THPS4 on PC is so ungodly choppy. There is a solution to this. Enable
V-sync by using your
graphics card control panel (I use NVIDIA GeForce GTX 970 so I was able to apply the setting to only the game's .exe instead of applying it to the main setting). This will make the game's max frame rate to 60. The reason why is because the game doesn't have a frame limit unlike the other THPS games. Due to this, it'll run at very high frame rates if played on a good computer, and running it on high frame rates cause stuttering.
P.S. I know that no one really plays THPS4 anymore, but I just wanted to share this since I saw others have this kind of problem.