Yeah don't expect much with a Pentium 4, even those with Core2Duo's/Quads/i7 still get lag on quite a few games, I am surprised that you were even able to achieve as high of frame rates as you did on such an old processor.
You'll either have to upgrade or live with it, since a Pentium 4 isn't going to run cpu intensive emulators such as Dolphin and Pcsx2 decently without lag and slowdowns. You may have better luck with 2D games or games with a minimal amount of 3D geometry.
As development progresses system requirements can either go up or go down, but even if system requirements do go down in the future I would honestly not expect to see a huge increase in performance with such a processor.
You'll either have to upgrade or live with it, since a Pentium 4 isn't going to run cpu intensive emulators such as Dolphin and Pcsx2 decently without lag and slowdowns. You may have better luck with 2D games or games with a minimal amount of 3D geometry.
As development progresses system requirements can either go up or go down, but even if system requirements do go down in the future I would honestly not expect to see a huge increase in performance with such a processor.