This page details the technical specifications of the Sega 32X.

Main CPU: 2x Hitachi SH-2 (SH7095) 32-bit RISC processors

Clock speed: 23.01136 MHz (NTSC), 22.801467 MHz (PAL)

Clock cycles: 46.022721 MHz (NTSC, 23.01136 MHz per SH-2), 45.602934 MHz (PAL, 22.801467 MHz per SH-2)

2x CPU cores: 32‑bit RISC instructions/registers, up to 4 instructions/cycle (2 instructions/cycle per SH-2), 1.3 MIPS per MHz, 59.829537 MIPS (NTSC, 29.914768 MIPS per SH-2), 59.283814 MIPS (PAL, 29.641907 MIPS per SH-2)

4x internal fixed‑point math processors: 2x MULT multiplier DSP, 2x DIVU division units, parallel processing

2x MULT multiplier DSP: 46.022721 MOPS (NTSC, 23.01136 MOPS per SH-2), 45.602934 MOPS (PAL, 22.801467 MOPS per SH-2)

2x DIVU division units: 16/32/64-bit division, 1,180,069 divides/sec

2x DMA units: 2x DMAC (Direct Memory Access Controller), parallel processing

Bus width: 64‑bit (2× 32‑bit) internal, 32‑bit external

CPU co-processors: Overlay/Underlay processors

Genesis CPU:

Motorola M68000 — 7.670453 MHz (NTSC), 7.600489 MHz (PAL), 16/32-bit instructions, 32-bit internal data bus, 16-bit external data bus, 1.342329 MIPS (NTSC), 1.330085 MIPS (PAL)

Zilog Z80 — 3.579545 MHz (NTSC), 3.546894 MHz (PAL), 8/16-bit instructions, 8-bit data bus, 0.519034 MIPS (NTSC), 0.514299 MIPS (PAL)

Sega CD CPU: Motorola M68000 — 12.5 MHz, 2.1875 MIPS

Graphics

32X graphics chip: Sega 32X VDP (Sega Custom LSI) @ 23.01136 MHz (NTSC), 22.801467 MHz (PAL)

Data bus width: 32-bit (16-bit per framebuffer)

Word length: 16-bit

Features: 3D polygon graphics, Gouraud shading, texture mapping, more sprites, quicker animation

Color palette: 32,768 colors

Double-buffered framebuffer with three modes:

8bpp "packed pixel" mode: 256 simultaneous colors on screen; each pixel is an index into CRAM (can use full screen)

16bpp "run length" mode: 256 simultaneous colors on screen; each pixel is both a number of pixels to display and the index of CRAM (limits screen size)

16bpp "direct color" mode: 32,768 simultaneous colors on screen; each pixel is the color value (limits screen size)

VRAM: 256 KB, split into two 128 KB segments for each framebuffer. A priority system allows partial overlaying/underlaying of Mega Drive/Mega-CD graphics.

Sprites, polygons and textures accessed from 256 KB main SDRAM and 4–8 MB ROM cartridge.

Resolutions: 320×224, 320×240, 320×204 (direct color), 320×408 (8bpp)

Overscan: 450×262 (NTSC), 450×313 (PAL)

Refresh rate: 60 Hz (NTSC), 50 Hz (PAL)

Maximum frame rate: 60 FPS (NTSC), 50 FPS (PAL)

Framebuffer bandwidth: 72.727272 MB/s (36.363636 MB/s per framebuffer)

SH-2: 36.363636 MB/s (read/write, 1 byte/cycle per SH-2)

32X VDP: 29.488906 MB/s (14.148 MB/s read, 15.340906 MB/s write)

68000: 1.917613 MB/s (read/write, 4 cycles/byte)

Framebuffer fillrate: 18.181818 MPixels/s (16bpp), 36.363636 MPixels/s (8bpp)

SH-2: 18.181818 MPixels/s (16bpp), 36.363636 MPixels/s (8bpp)

32X VDP: 7.670453 MPixels/s (16bpp), 15.340906 MPixels/s (8bpp)

68000: 958,806 pixels/s (16bpp), 1.917613 MPixels/s (8bpp)

3D polygon geometry calculations:

Polygon transformations: 260,000 polygons/sec

Lighting calculations: 230,000 polygons/sec (flat), 180,000 polygons/sec (Gouraud)

3D polygon rendering:

Flat shading: 160,000 polygons/sec

Gouraud shading: 100,000 polygons/sec

Texture mapping: 50,000 polygons/sec

Texture Gouraud shading: 40,000 polygons/sec

2D sprite/tile capabilities: Scrolling, scaling, rotation, alpha blending

Colors per sprite/tile: 128 (8bpp), 256 (8bpp), 8192 (16bpp), 32,768 (16bpp)

Tile size: 8×8 texels, 64 bytes (8bpp), 128 bytes (16bpp)

Sprite sizes: 8×8 to 320×240 texels, 64 bytes to 150 KB

Maximum sprites/tiles per frame: 3800 sprites/tiles (8bpp, 8×8, 237.5 KB), 1900 sprites/tiles (16bpp, 8×8, 237.5 KB)

Maximum sprites/tiles per scanline: 1463 texels, 182 sprites/tiles (8×8)

Overlay/Underlay

Overlay/Underlay graphics processors:

Genesis VDP — 13.423294 MHz (NTSC), 13.300856 MHz (PAL), 8/16-bit data bus

Sega CD ASIC — 12.5 MHz, 32-bit (2x 16-bit) data bus

Overlay/Underlay Genesis VDP planes: 512–1536 color palette, 61–512 colors on screen

Sprite plane: 80 sprites/frame, 8×8 to 32×32 pixels/sprite, 16 colors/sprite, maximum 1280 sprite tiles/frame

Background planes: 2 tiled scrolling background layers, 8×8 pixels/tile, 16 colors/tile, 320×224 tilemaps, maximum 1808 tiles/frame

Fillrate: 6.934358 MPixels/s (read), 6.41376 MPixels/s (write), 6.934358–36.325644 MPixels/s (effective tile fillrate)

Overlay/Underlay Sega CD ASIC planes: Enhanced Mega Drive VDP planes, enhanced FMV plane

Sprite/Tile planes: 128–1536 colors on screen, sprite/tile scaling and rotation

FMV plane: Full motion video, 32,768 colors on screen

Fillrate: 6.934358 MPixels/s (read/write), 6.934358–36.325644 MPixels/s (effective tile fillrate)

Sound

Sound chip: QSound PWM @ 23.01136 MHz (NTSC), 22.801467 MHz (PAL)

Stereo PWM (Pulse Wave Modulation) mixing with Mega Drive sound; additional 2 channels (12 channels in total)

11-bit PWM, stereo PCM output, surround sound

Memory

System RAM: 648.5–1368.5 KB total, 512 KB (4 MBit) additional RAM to Mega Drive or Sega CD memory

Main RAM: 256 KB SDRAM

VRAM: 256 KB FPM DRAM (dual 128 KB framebuffers)

Genesis RAM: 136 KB (64 KB main, 64 KB video, 8 KB sound)

Sega CD RAM: 856 KB (512 KB main, 256 KB video, 64 KB audio)

RAM Clear Hardware: 512 bytes (used for flat-shaded polygons)

Internal processor cache: 5 KB

SH-2: 4 KB (2 KB per CPU)

32X VDP: 1 KB, including 512 bytes (256 words) color palette RAM (CRAM)

Cartridge ROM: 4–8 MB

Bandwidth

System RAM bandwidth: 118.749992 MB/s (NTSC), 118.330206 MB/s (PAL), 3 data buses, 48-bit data bus width

SDRAM: 46.02272 MB/s (NTSC, 16-bit, 23.01136 MHz, 43ns), 45.602934 MB/s (PAL, 16-bit, 22.801467 MHz, 43ns)

VRAM: 72.727272 MB/s (32-bit, 18.181818 MHz, 55 ns, 16-bit per framebuffer, 36.363636 MB/s per framebuffer, 55ns cycles, 80ns access)

Cartridge bandwidth:

Game ROM: 13.333333 MB/s (16-bit, 6.666666 MHz, 150 ns) to 28.571428 MB/s (16-bit, 14.285714 MHz, 70 ns)

Non-volatile SRAM: 6.666666 MB/s (6.666666 MHz, 150 ns) to 14.285714 MB/s (14.285714 MHz, 70 ns)

Internal processor cache bandwidth:

SH-2: 184.09088 MB/s (92.04544 MB/s per SH-2, 32-bit per SH-2)

32X VDP: 92.04544 MB/s (32-bit, 23.01136 MHz), including 46.02272 MB/s (16-bit, 23.01136 MHz) color palette RAM