hackertube.io

[EPILEPSY WARNING] How fast should an unoptimized terminal run?

Molly Rocket · demo · Watch on YouTube

Software performance & optimizationTesting, debugging & developer tools

What it is

Casey Muratori shows how fast a terminal renderer can run, building a simple reference renderer that handles Unicode and colored text far quicker than Windows Terminal. He argues that common excuses for slow terminals do not hold up.

Why Hacker News recommends it

It is the canonical reference for the claim that modern software wastes hardware, and the proof-of-concept behind the Windows Terminal performance debate.

  • 6 people recommended it
  • 7 different months
  • 2 strong recommendations
  • first 2021, last 2026

What HN commenters said

  1. “See the epic demo (and stay till the end for color output)”

    Casey Muratori demos a fast reference terminal renderer

    dmitriid, 2021-07 · Strong recommendation · in “Apple and Intel first to use TSMC 3nm”

  2. “it's just so very very good, and snark aside, his perspective is extremely valuable”

    Series on implementing terminals with valuable software engineering perspective

    dundarious, 2022-05 · Strong recommendation · in “Windows Terminal Source Code”

  3. “Link to dev's presentation of their implementation that seems to run circles around microsoft's terminal”

    Presentation of an implementation that outruns Microsoft's terminal

    djoldman, 2022-05 · Recommendation · in “When I tell the Windows Terminal team something is simple, I am "misguided"”

  4. “Casey Muratori excoriated the Windows Terminal dev team for failing to achieve a consistent 60 fps when displaying fixed-width text”

    Shows terse, fast code outperforming the Windows Terminal team's work

    jiggawatts, 2022-09 · Recommendation · in “Why modern software is slow”

  5. “After watching an inspiring video on terminal optimization [1]”

    Inspired the author to estimate how fast programs should run

    surprisetalk, 2023-11 · Recommendation · in “Compressing Codebase Collocates”

  6. “Casey spent <1 week making RefTerm, a skeleton proto-terminal with the same constraints Microsoft people had”

    RefTerm demo showing simple code can beat Windows Terminal massively

    jodrellblank, 2025-07 · Recommendation · in “Fast”

Excerpts from Hacker News comments, linked to the originals. Summaries and labels were written by a language model from those comments.

Topics: terminal rendering, casey muratori, windows terminal, refterm, optimization

Also recommended by the same people