Stuttered scrolling on some cores

hello, I have a windows retroarch install working almost perfectly. I mainly use 2 cores (FbNeo & Mame2003-plus). On some games (Wonder Boy), horizontal scrolling is nearly perfect on FbNeo, and very stuttered on Mame2003plus.

As RA config are the same regarding drivers and so on, I assume it’s a core issue. Is there any hint to improve this situation ?

Thanks