The NAOMI (New Arcade Operation Machine Idea) is also Japanese for beauty above all else.
In 2000, Sega debuted the NAOMI 2 arcade system board at JAMMA. NAOMI 2 offered improved graphics performance; by substituting the graphics-assembly of the previous NAOMI board with a new assembly composed of two PowerVR CLX2 GPUs and a VideoLogic Elan chip (for geometry transformation and lighting effects). NAOMI 2 also doubled the NAOMI's graphics memory from 16MB to 32MB, to enable more detailed graphics (each CLX2 has its own 32MB bank, as the CLX2 does not share graphics RAM). Architecturally, the NAOMI 2 is similar enough to the original NAOMI that both can play NAOMI games without modification.
With the NAOMI 2, Sega brought back the GD-ROM drive. For both NAOMI and NAOMI 2, the GD-ROM setup was offered as an optional combination of daughterboard expansion known as the DIMM Board, and the GD-ROM drive itself. The DIMM board contained enough RAM to allow an entire game to be loaded into memory at start up, allowing the drive to shut down after the game has loaded. This heavily reduces load times during the game, and saves on drive wear and tear.