The phrase "" typically refers to massive, pre-curated collections or "builds" of retro games designed to be compatible with the RetroArch emulation frontend. While individual ROMs are just game files, these large sets are often marketed as all-in-one solutions for users looking to quickly set up a library of thousands of titles across multiple systems like NES, Genesis, and SNES. How to Use Large ROM Sets in RetroArch
| System | Core Name | Ideal ROM Count | Storage Space | | :--- | :--- | :--- | :--- | | | FCEUmm / Mesen | 1,400 | ~200 MB | | Super Nintendo (SNES) | Snes9x | 1,750 | ~1.5 GB | | Sega Genesis | Genesis Plus GX | 900 | ~500 MB | | Game Boy / GBC | Gambatte | 1,200 | ~200 MB | | Game Boy Advance | mGBA | 1,500 | ~4 GB | | MAME (Arcade) | MAME Current | 1,500 (parents only) | ~15 GB | | PlayStation 1 | PCSX-ReARMed / SwanStation | 700 (CHD format) | ~60 GB | | TurboGrafx-16 | Beetle PCE | 300 | ~100 MB | RetroArch 9000 ROMs