Thank you for the explanation, I am not to used to frequent this forums so I got scolded. There is a reason why I insist on using MAME over other options and that's because it have ironically another useful option called overclocking...
You know SNES games are plagued with all kinds of slowdowns, I dealt with it as a kid but why will I be tortured again by that? Since I already overclocked the Snes driver I am having a blast on MAME playing the compatible games that works on it...
The only thing that annoys me is the shader not scaling correctly on this emulator (not a fault of MAME itself as pointed by Haze) but I would want to "fix" it even if this would be an ugly hack...