For Forza Horizon 5players, if you have the problem of stuttering, this guide provides a possible solution for you to fix the problem.
Possible fix
A lot of you have problems with stuttering.
It seems there is a problem with hyper-threading (CPU).
I disabled hyper-threading in my UEFI/BIOS and for the most time, the stutters are gone.
It is just a temporary fix, hope the developers fix the game soon.
Benchmark with HT (CPU limit):
Benchmark without HT (GPU limit):
Without hyper-threading the CPU Render is much smoother than bevor.