"Fantom X doesn't have onboard ROM memory for user storage"

Preset Memory Patches: 1024 + 256 (GM2), Rhythm Sets: 40 + 9 (GM2), Performances: 64

User Memory Patches: 256, Rhythm Sets: 32, Performances: 64

Card Memory Patches: 256, Rhythm Sets: 32, Performances: 64

In Addition to that you have 16 MB internal Flash RAM for sample and sequence data storage.

And you can expand the sample and sequence data storage with Flash cards upto 1GB.