I don't think they are specific drivers because usually MAME when it needs something specific requires it and makes you put it together with the roms. As I told you, they are a whole series of slightly more recent games, from a certain year onwards everyone does it. I've noticed this on all titles that are newer and from the late 90's onwards. I am sure that it is about optimizing the code because you understand that being a bit bigger games, it is already difficult to manage everything and if you start them with a much more modest hardware but based on X86, then the same games, with the same Roma, they go perfect. It's all about MAME on Power!
In my opinion the main problem is that this MAME on Power is simply a transposition from X86, not being written on Power, it does not exploit our processor at all and being a simple transposition, it has all the limits of the case unfortunately ...
