Many 3D arcade games (Nintendo 64-based, Namco System 22) use CHD files (Compressed Hunks of Data). In a Split set, a CHD lives outside the zip. In a set for MAME 2003-Plus:
A is widely considered the "gold standard" for retro gaming on low-power devices like the Raspberry Pi, PlayStation Classic, and Android handhelds. Mame 2003-plus Reference Full Non-merged Romsets