How to configure Braiins OS+ for autotuning? (Antminer firmware)

Understanding Braiins OS+ Autotuning Fundamentals

1. Braiins OS+ is a Linux-based firmware replacement for Bitmain Antminers, designed to enhance efficiency, stability, and real-time monitoring capabilities.

2. Autotuning is an embedded feature that dynamically adjusts voltage, frequency, and fan speed based on chip temperature, power draw, and hashboard performance metrics.

3. Unlike factory firmware, Braiins OS+ executes autotuning at boot and continuously refines parameters during operation without requiring manual intervention.

4. The process relies on proprietary algorithms trained on thousands of ASIC chip behavior profiles across varying ambient conditions.

5. Autotuning operates independently per hashboard, allowing heterogeneous tuning when board-level thermal or electrical characteristics differ significantly.

Prerequisites Before Enabling Autotuning

1. Ensure the miner is running Braiins OS+ version 22.08 or later — earlier versions lack full autotuning support for S19j Pro, T21, and L7 models.

2. Confirm stable network connectivity and SSH access; autotuning configuration is performed exclusively via command line or API endpoints.

3. Verify all hashboards report “online” status in the web interface under System → Hardware Status; offline boards prevent autotuning initialization.

4. Disable any third-party overclocking scripts or cron jobs that manipulate /sys/class/hwmon/ entries or write directly to /proc/braiins/ interfaces.

5. Perform a clean reboot after firmware installation — residual kernel modules from stock Bitmain firmware can interfere with sensor calibration.

Activating Autotuning via CLI

1. Connect to the miner via SSH using the default credentials: root / root.

2. Run sofware-autotune enable — this command writes the autotune flag to persistent storage and triggers immediate sensor profiling.

3. Monitor progress with tail -f /var/log/autotune.log; successful initialization displays “Profiled 3/3 hashboards” followed by “Autotune active: true”.

4. Use bmminer-api get_autotune_status to retrieve real-time tuning state, including current VDD, frequency offsets, and thermal headroom values.

5. Avoid interrupting the first 90-minute learning window — premature reboot resets the calibration cycle and forces re-profiling.

Verifying Autotuning Behavior

1. Navigate to the web UI and open Miner → Tuning; autotuned values appear under “Active Settings” with green indicators next to each parameter.

2. Observe the “Thermal Map” visualization — it renders live temperature gradients across chips using color-coded hexagons, updated every 5 seconds.

3. Cross-check power efficiency: compare W/GH before and after autotuning activation using the Statistics → Efficiency History chart over a 24-hour span.

4. Inspect fan curves under System → Cooling; autotuned fans respond to localized hotspots rather than average board temperature.

5. Review the Logs → Autotune Events tab for entries like “Reduced core voltage on HB2 by 25mV due to sustained 78°C junction temp”.

Frequently Asked Questions

Q: Can autotuning be disabled without reflashing?A: Yes. Execute software-autotune disable via SSH, then reboot. All settings revert to factory defaults stored in /etc/braiins/tuning.json.

Q: Does autotuning modify ASIC firmware or only runtime registers?A: It modifies only volatile registers. No changes are written to the ASIC’s internal ROM or bootloader; all adjustments vanish on power loss unless saved manually.

Q: Why does autotuning show “Insufficient data” for one hashboard?A: This indicates inconsistent sensor readings — typically caused by cracked thermal pads, oxidized temperature sensor contacts, or damaged I²C bus traces on that board.

Q: Is autotuning compatible with Braiins OS+ Pool Hopping?A: Yes. Autotuning runs independently of pool selection logic. Frequency and voltage adjustments persist regardless of whether the miner connects to Slush Pool, Foundry, or a private stratum endpoint.