Firmware (LuxOS)
Temps and Fans

Temperature & Fans

LuxOS provides three user-customizable temperatures that drive different actions in the miner.

Temperatures reported by LuxOS are hashboard temperatures and shall not be confused with chip temperatures. For most S19 series miners, stock and other alternative aftermarket firmware's estimate chip temperatures by adding ~15C to the hashboard temperature sensors readings. Since chip temperatures are estimations, LuxOS shows hashboard temperatures only.

Most miners will have 4 temperature sensors per hashboard, although there are a few exceptions of miners coming with 2 temperature sensors per hashboard. LuxOS makes decisions based on the highest reading across all hashboard temperature sensors.

  • Target Temperature: Used for the fan algorithm. Once the maximum temperature reading reaches the Target Temperature threshold fan speeds will be set to 100% unless the LuxOS fan algorithm is overridden with Manual fans settings.

  • Hot Temperature: Used by ATM (Advanced Thermal Management) to drive steps up and steps down in profiles.

  • Dangerous Temperature: When any of the temperatures in a hashboards reaches this temperature the hashboard will be shutdown to prevent damage.

Temperature SettingDefaultFiber Glass HashboardsAluminium Hashboards
Target Temperature55C55C55C
Hot Temperature65CFor units with ATM enabled and if the user wants to experience less underclocking then increase this setting.To preserve the lifespan of the miner we don't increasing the hot temperature for sustained periods of time.
Dangerous Temperature70CMaximum of 75C, ideally a 5C buffer from your Hot Temperature for ATM to have enough room to cool-down a miner before it shuts down due to high temperatures.Maximum of 72C, ideally a 5C buffer from your Hot Temperature for ATM to have enough room to cool-down a miner before it shuts down due to high temperatures.

Automatic Fan Control

LuxOS provides a fan algorithm that automatically adjusts fan speeds based on the temperature of the miner. The fan algorithm is designed to keep the miner at the target temperature set by the user. LuxOS reads temperatures from the temperatures sensors once every seconds and adjusts fan speeds accordingly.

The following scenarios have a different fan behavior:

  1. If temperatures can't be read from any temperature sensor, the PSU is enabled and at least one hashboard is detected (regardless if it's enabled or disabled), fans will be set to 100% for safety reasons.
  2. If temperatures can't be read from any temperature sensor, the PSU is disabled or no hashboard is detected, fans will be set to 20%.
  3. If the miner is curtailed, fans will be set to 20%.

Manual Fan Control

If users wish to override the automatic fan control, they can set the fans to a specific percentage. In this scenario, LuxOS won't adjust the fan speed dynamically based on temperature. We suggest keeping the fans set to Automatic mode for the best performance and longevity of the miner. If immersion mode is enabled, all fans will be disabled entirely.

Cold Start

Warming up miners correctly is crucial for a reliable operation and improved LuxOS Tuner performance in cold environments. Miners that are excessively cold and don't warm up properly won't tune as well as properly warmed-up miners.

To tackle warming up miners, if during the initial boot any temperature sensor is below 30C LuxOS will increase the initialization voltage to the maximum allowed by the PSU -most PSUs will go up to 15v-.

If at any time during initialization all temperature sensors report above 30C LuxOS will ramp down voltage back to its target before continuing increasing frequency. This is the most likely scenario were voltage comes down before we achieve nominal hashrate.

If the miner is in an extreme cold environment, then it will continue to ramp frequency at 15v. Only after reaching target frequency it wil start coming down in voltage to the profiles target. However, If the autotuner is enabled then LuxOS Tuner will be responsible to decrease voltage progressively after finish ramping to the target frequency.