How Game Streaming on Twitch and YouTube Works: The Basics

How Game Streaming Works

When you stream, software (usually OBS or Streamlabs OBS) captures your screen, encodes the video in real time to H.264 or H.265 format, and uploads it continuously to Twitch or YouTube's ingest servers at a fixed bitrate (your internet upload speed is the limiting factor).

The Encoding Task

Encoding is computationally expensive. You have three options: GPU encoding (NVENC/AMD VCE): Offloads encoding to dedicated hardware on your GPU. On NVIDIA RTX cards, NVENC produces excellent quality at near-zero game performance impact. This is the recommended approach for most streamers. CPU encoding (x264): Runs on your CPU. Produces higher quality at a given bitrate but consumes significant CPU capacity. On a 12-core CPU, x264 at the "medium" preset uses roughly 40% of CPU during gaming. Quick Sync (Intel): Intel's dedicated encoder. Fast with minimal impact; quality between NVENC and x264.

Bitrate: How Much Upload Do You Need?

• 1080p 60 FPS (Twitch): 6,000 kbps upload minimum; 8,000 kbps preferred
• 1080p 30 FPS: 4,500 kbps
• 720p 60 FPS: 3,500–4,500 kbps

Twitch non-partner limit: 6,000 kbps. Partners get higher limits.

OBS Scene Setup

Create at least two scenes: a game scene (game capture + microphone) and a BRB/starting scene. Use Game Capture (not Window Capture) for best performance. Enable "Capture only the fullscreen game" for DirectX games.

Dual PC Streaming

If streaming causes game performance issues, a dedicated streaming PC (even a modest Ryzen 5 2600) handles x264 encoding while the gaming PC runs the game via NDI or capture card. This is the professional streamer approach.