Antminer S9j Firmware _verified_ May 2026

| Firmware | Hashrate (TH/s) | Wall Power (W) | Efficiency (J/TH) | Chip Temp (°C) | |----------|----------------|----------------|-------------------|----------------| | Stock (Bitmain 13.5TH) | 13.4 | 1,322 | 98.6 | 82 | | Braiins OS (Eco) | 12.1 | 950 | 78.5 | 68 | | Braiins OS (Turbo) | 15.8 | 1,880 | 119.0 | 94 | | Vnish (Ultra) | 17.9 | 2,450 | 136.9 | 108† |

At 108°C, the BM1387 chips begin to desolder themselves from the PCB (reflow phenomenon). Modified firmware disables the default 95°C shutdown, enabling this high-risk mode. 4. The ASICBoost Controversy The S9j’s firmware contains dormant code for ASICBoost (patented by Green Revolution Cooling, later acquired). By reordering nonce bits, the miner reduces work by ~12.5%. Stock firmware ignores this; modified firmware (especially Braiins) activates it aggressively. antminer s9j firmware

If you attempt to flash Vnish Ultra, ensure you have a separate breaker and a Class C fire extinguisher nearby. Suggested citation: Hacker, C. (2024). Beyond the Hashrate Ceiling: Reverse Engineering the Antminer S9j Firmware . Journal of Low-Cost Cryptomining, 3(2), 45-53. | Firmware | Hashrate (TH/s) | Wall Power

† Thermal throttling engaged after 15 minutes; requires immersion cooling. If you attempt to flash Vnish Ultra, ensure