Raster Scan vs. Random Scan: Key Differences & Which Display Tech Wins
Raster Scan paints every pixel row by row like a TV; Random Scan draws only the endpoints of lines, like an Etch-A-Sketch with a laser.
People confuse them because both drove early CRTs, yet one powered your childhood Nintendo while the other guided Cold-War jet simulators—same glowing glass, opposite philosophies.
Key Differences
Raster Scan redraws the entire frame 60–120 times per second, perfect for rich color images. Random Scan updates only the vectors that change, delivering crisp wireframes at lightning speed but struggling with complex fills.
Which One Should You Choose?
Pick Raster Scan for TVs, phones, and gaming. Choose Random Scan only if you’re maintaining vintage CAD radar displays or building a retro vector-graphics arcade cabinet.
Can modern GPUs emulate Random Scan?
Yes, through vector shaders, but the analog glow and instant response are hard to replicate digitally.
Why did Raster Scan dominate?
Cheaper RAM and color TV demand made full-frame buffers affordable, pushing vector tech into niche heritage status.