Sega Naomi Arcade Motherboard is SEGA next generation arcade hardware after Model 3 Step 2.1. Naomi and Dreamcast are almost identical in that they both share the same CPU (Hitachi SH-4 200 MHz), same GPU (PowerVR Series2 100 MHz), and the same 64 channel ARM7 based sound system (Yamaha AICA 45 MHz). The main difference will be in the amount of main RAM, the amount of graphics RAM, the amount of sound RAM, and the storage option, with the Naomi board allowing banks of ROM chips for game storage. There is no option for SEGA's special GD-ROM (1.2 GigaByte Disk-ROM) on the Naomi.