Audience: Everyone

CD Mode vs USB Mode

NeuralDrive's hybrid ISO image can be used in two distinct ways: as a live environment from a USB drive or as a read-only system from a CD/DVD. The choice of medium significantly impacts the features and persistence of the system.

When NeuralDrive is flashed to a USB drive, it creates a persistence partition that allows for the full suite of features. This is the intended deployment method for most users.

  • Persistence: Models, system configurations, and user data are saved to the USB drive and survive reboots.
  • Model Management: Downloading and updating models via the WebUI or command line is fully supported.
  • Performance: USB 3.0+ provides acceptable I/O speeds for system operations.

CD Mode

If the ISO is burned to a CD or DVD, or booted in an environment where the boot medium is read-only, NeuralDrive operates in a restricted live mode.

  • Read-Only System: All system changes are made to a tmpfs (RAM-based filesystem) and are lost upon reboot.
  • Disabled Downloads: Since there is no persistent storage on the disc, model downloads are disabled. Users will see a warning: "Downloads disabled — connect external storage."
  • Stateless Security: Every boot starts with a clean, known state, making it ideal for high-security environments where no data should remain on the hardware.

Booting to RAM

For CD mode, a specialized "Copy to RAM" (toram) boot option is available in the boot menu. This loads the entire image into system memory, which has several benefits:

  • Speed: Operating purely from RAM is faster than reading from an optical drive.
  • Drive Availability: Once loaded, the CD can be ejected, freeing the drive for other uses.
  • Hardware Compatibility: Requires sufficient RAM (typically 16GB+) to hold both the system and the models.

Comparison and Use Cases

FeatureUSB ModeCD Mode
PersistenceFullNone (lost on reboot)
Model DownloadsEnabledDisabled (unless external storage added)
EncryptionSupportedNot applicable
Typical Use CasePermanent local LLM serverEvaluation, high-security workstations

When to Use Each

  • USB: Best for regular use, developing with LLMs locally, or setting up a dedicated server for a small team.
  • CD: Best for testing hardware compatibility, air-gapped security needs, or environments where the operating system must never be modified.

Tip: If using CD mode but still needing persistent model storage, you can connect a separate USB or SATA drive. NeuralDrive will automatically detect and mount it. For more, see External Storage.

For the initial setup process on either medium, refer to First Boot Setup.