StarPilotHardware and wiringSome effort

Chestnut with StarPilot on comma 3, 3X and four

You only need chestnut for the biggest models; StarPilot detects it at boot and hides GPU models when it is missing.

comma four with its screen on

Who this is for

StarPilot users wondering whether to buy chestnut.

comma fourcomma 3Xcomma three

You need

  • A comma device running StarPilot
  • A chestnut kit from comma
  • 12 V power and a place for the GPU box

In plain words

Why this guide matters

StarPilot owners keep asking whether comma's chestnut GPU box is worth buying. This page explains that only models marked as needing a GPU require it, and the fork hides those models when chestnut is absent. You learn what changes at boot, which kit to buy, and how to pick a GPU model afterwards.

The short version

What the full guide walks you through

  1. Decide whether you want models marked as needing a GPU.

  2. Buy the dock-only or ready-to-drive kit.

  3. Mount the box and connect power and USB.

  4. Pick a GPU model in the model manager once detected.

Before you start

  • StarPilot claims comma 3 and 3X support; comma itself only supports chestnut on comma four.

The full written guide belongs to StarPilot. Checked on September 10, 2026.

Quick answers

Questions people ask

Does StarPilot support chestnut on a comma 3X?

StarPilot's wiki says yes for comma three, 3X and four, but comma only supports the comma four. Treat older-device use as unverified.

What happens if I unplug chestnut?

StarPilot checks for chestnut at boot and falls back to a built-in model if your chosen model needs a GPU.

Which model should I start with?

The wiki suggests a standard on-device model first. Try a chestnut-class model only after the basics work.

Related

All community guides

Not sure this is your path?

Check your exact car first, then choose software and hardware.

Photos: comma.ai. Guide content belongs to StarPilot. CommaGuide is an independent guide and is not affiliated with comma.ai or StarPilot.

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