If you manage to obtain a working copy, Pokémon X is widely praised for its:

requires approximately of space (about 14,000 blocks) on a 3DS SD card.

Best for installing directly onto a 3DS console with Custom Firmware (CFW).

A Nintendo 3DS ROM is structured as a Nintendo Content Structure (NCSD) container. Inside this container are NCCH partitions. These partitions house the game executable ( .code ), game assets (models, textures, audio), and the manual/manual data.