Comment by TinkersW

FEX is a CPU JIT, so your GPU settings are irrelevant to it, it is translated but not by FEX, and there is no real perf hit for the GPU

The old games don't really matter with regards to FEX perf, so the only relevant bit is the semi newer games at 30/40 fps, which seems very slow to me, given that you are only running at 1080p/Medium, so you likely have a CPU bottleneck there.