Pixel

Pixel is a contraction of Picture Element. A single, indivisible unit that makes up an image when used in conjunction with many (perhaps thousands or millions) other pixels. Typically, the visible part of the Mega Drive screen consists of 71,680 pixels, since it has a display resolution of 320×224.

Units

• 1 megapixel (MPixel) = 1 million pixels
• 1 gigapixel (GPixel) = 1 billion pixels (1000 MPixels)

Fillrate

The term fillrate refers to the number of pixels a video card or graphics chipset can render in a second, and the number of pixels it can write to video memory. This is also known as the rendering fillrate.

The units used to measure fillrate:

• 1 megapixel/sec (MPixel/s) = 1 million pixels per second
• 1 gigapixel/sec (GPixel/s) = 1 billion pixels per second (1000 MPixels/s)

Fillrates for graphics processors in Sega consoles:

• TMS9918 (SG-1000) — 3.579545 MPixels/s (read), 1.789772 MPixels/s (write)
• VDP (Master System) — 5.369317 MPixels/s (read), 1.789772 MPixels/s (write)
• YM7101 VDP (Mega Drive) — 6.934358 MPixels/s (read), 6.41376 MPixels/s (write), 6.934358–36.325644 MPixels/s (effective tile fillrate)
• 32X VDP (32X) — 17.897725 (15-bit color), 35.79545 MPixels/s (8-bit color)
• VDP1 (Saturn) — 28.6364 (15-bit color), 57.2728 MPixels/s (8-bit color)
• VDP2 (Saturn) — 14.21875–114.5456 MPixels/s (bitmap), 114.5456–503.31648 MPixels/s (effective tilemap fillrate)
• PowerVR CLX2 (Dreamcast) — 3.2 GPixels/s (opaque polygons), 500 MPixels/s (translucent polygons)

For the fillrates of Sega arcade systems, see List of Sega arcade systems.

Texel

A texel (texture element or texture pixel) is the fundamental unit of texture space. Textures are represented by arrays of texels, just as pictures are represented by arrays of pixels.

Units

• 1 megatexel (MTexel) = 1 million texels
• 1 gigatexel (GTexel) = 1 billion texels (1000 MTexels)

Texture Fillrate

• 1 megatexel/sec (MTexel/s) = 1 million texels per second
• 1 gigatexel/sec (GTexel/s) = 1 billion texels per second (1000 MTexels/s)

The texture fillrate was the same as the rendering fillrate for Sega consoles up until the Sega Saturn. The Sega Dreamcast has differing fillrates for rendering and texturing. For Sega arcade systems, it varies depending on the hardware.