And then, there were the (Compressed Hunks of Data).
If you are building a bartop arcade using a Raspberry Pi 3 or 4, the MAME 2003 core provides 60 FPS (frames per second) on almost the entire library. Modern MAME versions might struggle with the same games on this hardware. MAME 2003 Reference Set - MAME 0.078 ROMs- CHDs...