Why Are Modern Games So Big?

tim-cain game-development art optimization file-size compression

Abstract

Problem: Why have modern video game file sizes ballooned compared to older titles?

Approach: Tim Cain walks through every major contributor to game size — resolution, textures, models, animations, video, sound, code, and compression trade-offs — drawing on decades of industry experience.

Findings: Art is overwhelmingly the largest contributor. Higher screen resolutions demand bigger textures and denser meshes, compounded by level-of-detail storage (multiple versions per asset). Longer games with more variety multiply this further. Sound, code, and reduced compression also contribute, but pale next to art.

Key insight: The short answer is one word: art. Everything else has grown too, but art assets at modern resolutions dwarf all other factors combined.

1. The Short Answer

Tim opens with his characteristically dry humor — "I'm frequently asked why is it so big?" — before delivering the one-word answer: art. The rest of the video is the long answer for those who want the details.

2. Resolution Escalation

Screen resolutions have grown enormously over the decades:

  • EGA/CGA era: 160×120
  • VGA: 320×200 or 320×240
  • SVGA: 640×480
  • HD: 1920×1080 (~6 MB of raw pixel data in 24-bit color)
  • 2K: 2560×1440 (~12 MB)
  • 4K: 3840×2160 (~24 MB)

Each jump roughly doubles the pixel data. This matters because every texture in a 3D game must scale with screen resolution to still look good. Higher-resolution screens demand higher-resolution textures, which demand more storage.

3. The Compounding Effect: LOD and Multi-Resolution Assets

It gets worse. Optimization techniques like level of detail (LOD) require storing multiple versions of both textures and models — a 4K version for close-up, a 2K version for mid-range, and an HD version for distant objects. This avoids expensive runtime downsampling but multiplies storage requirements.

4. Frame Rate Drives Animation Size

Frame rate expectations have escalated from 30 fps to 60, then 120, with 240 fps on the horizon for competitive esports. Higher frame rates demand denser, more complex animations so movement looks smooth without interpolation between frames. More animation keyframes means more data.

5. Video Content Explosion

Older games had little to no video — maybe a single opening cinematic. Modern games are packed with cutscenes, multiple cinematics, animated splash screens, and logo sequences. All of this video is rendered at higher resolution and higher frame rate, consuming enormous storage.

6. Lighting Complexity

Modern lighting requires far more than a simple texture. Each surface may need:

  • Normal maps for surface detail
  • Diffusion maps for light scattering
  • Subsurface scattering maps for realistic skin rendering

Tim admits he's not a graphics programmer but recalls asking artists "what are all those extra maps?" — they exist to make materials look realistic under varying lighting conditions rather than plasticky.

7. Longer Games, More Variety

Game length expectations have grown dramatically. A 5–10 hour game was once acceptable; now 40 hours is standard, with some RPG players expecting 100+. Longer games demand:

  • More maps with diverse environments (forests, deserts, snow, coastlines — not just grassland)
  • More items — weapons, armor, props — each needing multiple models (inventory view, ground model, wielded model)
  • More special effects — players expect unique visual effects per spell or ability, all at high resolution with quality sound

8. Sound, Code, and Other Contributors

8.1. Sound

Modern games ship with vastly more music, voice-over (sometimes 100,000+ lines), and sound effects. These are stored at much higher quality — high bit-depth, stereo, sometimes 5.1 surround — compared to the compressed 8-bit mono WAV files of the floppy era.

8.2. Code

Bigger games with more features naturally have more code. Additionally, using engines and libraries often pulls in entire modules even when only one feature is needed. Still, code is small relative to art.

9. The Compression Trade-Off

Games used to aggressively compress assets to fit on floppies or CDs, with players choosing between "small on disk" (slower loading) or "decompress to hard drive" (faster loading). Modern players expect near-instant load times and no loading screens. Decompressing assets on-the-fly while maintaining high frame rates and demand-loading textures around corners is problematic. The solution: store assets uncompressed or lightly compressed, which makes everything bigger on disk.

10. Summary

Everything in games has gotten bigger — sound, code, video, animations — but art is the dominant factor by far. Higher resolutions, multiple LOD versions, more environments, more items, more effects, and less compression all compound to produce the massive file sizes we see today.

Source: Tim Cain — "Why Are Modern Games So Big?"

11. References