Metal GPU Rendering

Updated March 22, 2026

Crystl uses Apple’s Metal framework to offload terminal rendering to the GPU. This means smoother scrolling, lower CPU usage, and better performance when working with large outputs.

How It Works

With Metal rendering enabled, Crystl sends text and glyph data to the GPU for compositing instead of relying on the CPU for every frame. The GPU handles glyph rasterization, cursor blending, and screen composition in parallel, freeing the CPU to focus on shell processes and Claude Code sessions.

What You’ll Notice

  • Smoother scrolling — Large command outputs and log streams scroll without stutter
  • Lower CPU usage — The CPU isn’t bottlenecked on drawing text, so your machine stays cooler and more responsive
  • Faster rendering — Screen updates are snappier, especially when Claude produces long outputs or when tailing verbose logs

Toggling Metal Rendering

Metal rendering is on by default. To toggle it:

  1. Open Settings > General (Cmd + ,)
  2. Find GPU Rendering
  3. Toggle on or off

Changes take effect immediately — no restart needed.

When to Disable

Most users should keep Metal rendering on. You might want to disable it if:

  • You’re running on a Mac with limited GPU resources and notice graphical glitches
  • You’re troubleshooting a display issue and want to rule out the GPU pipeline

Availability

Metal GPU rendering is available in both Free and Guild tiers.