The Bitmain Antminer S19j was a cost-optimized variant of the S19 platform, released in June 2021 as Bitmain expanded the S19 family to serve different market segments. Delivering 90 TH/s at 3,250W, the S19j achieved an efficiency of 36.1 J/TH — positioning it between the base S19 (34.2 J/TH) and the T19 (37.5 J/TH) in efficiency. The “j” designation indicates a revision using an optimized PCB layout and power delivery system that reduced manufacturing costs while maintaining competitive performance.
The S19j was released during a period of intense demand for mining hardware, driven by Bitcoin’s price rally in 2021. Bitmain produced the S19j in high volumes to meet demand, resulting in a large installed base worldwide. The miner uses the same BM1398 chip architecture and physical chassis as the rest of the S19 family, ensuring compatibility with existing infrastructure, firmware, and parts.
In 2026, the S19j is available at very low prices on the secondary market. Its performance sits in the middle of the S19 family — not as efficient as the S19 Pro but slightly better than the T19. For budget mining, space heater conversions, and home mining setups, the S19j offers strong value. D-Central Technologies provides full repair and conversion services for the entire S19 family.
Antminer S19j Full Specifications
| Specification | Details |
|---|---|
| Manufacturer | Bitmain |
| Model | Antminer S19j |
| Release Date | June 2021 |
| Algorithm | SHA-256 |
| Hashrate | 90 TH/s (±5%) |
| Power Consumption | 3,250W (±5%) |
| Efficiency | 36.1 J/TH |
| Input Voltage | 200–277V AC |
| Dimensions | 400 × 195 × 290 mm |
| Weight | 14.2 kg |
| Noise Level | ~75 dB |
| Operating Temperature | 5–45°C |
| Humidity | 5–95% |
| Cooling | 4 × high-speed fans |
| Network Connection | Ethernet (RJ45) |
| ASIC Chip | BM1398 (7nm) |
| Chips per Hashboard | 62 |
| Number of Hashboards | 3 |
| Total Chip Count | 186 |
| Power Supply | Integrated APW12 PSU |
Performance Analysis
At 36.1 J/TH, the S19j sits in the middle of the S19 family lineup. It is 5.6% less efficient than the base S19 (34.2 J/TH) and 22% less efficient than the S19 Pro (29.5 J/TH). Compared to the T19 (37.5 J/TH), the S19j holds a slight 3.7% efficiency advantage. Against the next generation, the S21 (17.5 J/TH) is roughly twice as efficient per terahash.
The S19j delivers 90 TH/s — 5 TH/s less than the base S19 (95 TH/s) but 6 TH/s more than the T19 (84 TH/s). This middle-of-the-road performance, combined with typically lower secondary market prices than the S19 or S19 Pro, makes the S19j an attractive budget option.
Daily and Monthly Power Costs
| Electricity Rate | Daily Power Cost | Monthly Power Cost | Viability |
|---|---|---|---|
| $0.05/kWh | $3.90 | $117 | Profitable — solid margins with cheap electricity |
| $0.08/kWh | $6.24 | $187 | Marginally profitable — monitor difficulty trends |
| $0.10/kWh | $7.80 | $234 | Breakeven — dual-purpose space heater recommended |
| $0.12/kWh | $9.36 | $281 | Unprofitable — space heater conversion or undervolting needed |
Heat Output
The S19j produces approximately 11,089 BTU/h of heat (3,250W × 3.412 BTU/W) — the same as other 3,250W S19 variants. This is equivalent to a large space heater and can meaningfully heat a room, garage, or workshop. See our Best Miners for Space Heaters guide for comparisons across models.
Best Use Cases in 2026
Budget Mining: The S19j is often the cheapest S19-family miner on the secondary market, making it the best value for miners who want S19-generation reliability without the premium pricing. For operations with electricity under $0.08/kWh, the S19j delivers competitive returns on minimal capital investment.
Space Heater Conversion: At ~11,100 BTU/h, the S19j provides the same heating capacity as the S19 and S19 Pro. D-Central offers Bitcoin Space Heater conversions for the entire S19 platform.
Home Mining: The S19j shares the same proven chassis, APW12 PSU, and firmware support as the rest of the S19 family. For home miners, the lower acquisition cost means less capital at risk. Pair with a cooling shroud to duct heat into living spaces during winter.
Undervolting: Like all S19-family miners, the S19j benefits significantly from undervolting with Braiins OS+ or Vnish. Power-capping to ~2,500W while maintaining 70-80 TH/s improves efficiency and extends profitability. See our Complete Undervolting Guide.
Common Issues & Repair
The S19j shares the reliability profile of the S19 family:
- Hashboard chip failures: BM1398 chips can fail after extended operation, causing missing chains or reduced hashrate. See our Chain X Only Fix Guide.
- APW12 PSU degradation: The integrated power supply can develop issues over time. See our APW12 PSU Repair Guide.
- Temperature warnings: Over-temperature shutdowns from restricted airflow or degraded thermal paste. See our Temp Too High Fix Guide.
- EEPROM errors: Corruption can prevent hashboard detection. See our EEPROM Error Fix Guide.
D-Central offers professional Antminer S19j Repair services from our Canadian workshop. See our ASIC Repair Cost Estimator for pricing.
D-Central Services for the Antminer S19j
- Repair: Hashboard, PSU, control board repair — Antminer S19j Repair
- PSU Service: APW12 diagnostics and repair — APW12 PSU Guide
- Space Heater Conversion: Home heating setup — Bitcoin Space Heaters
- Undervolting: Power optimization — Undervolting Guide
- Replacement Parts: Hashboards, fans, PSU — Shop Parts
- Repair Cost Estimate: ASIC Repair Cost Estimator
Frequently Asked Questions
Is the Antminer S19j still profitable in 2026?
The S19j is profitable at electricity rates below $0.08/kWh. At $0.05/kWh, it generates solid margins. With undervolting, profitability extends to slightly higher rates. As a space heater, the economics are favorable during heating season at any electricity rate.
How much electricity does the Antminer S19j use per day?
The S19j consumes approximately 3,250W continuously, translating to 78 kWh per day or about 2,340 kWh per month. At $0.10/kWh, that is $7.80/day or $234/month. Undervolting can reduce consumption to approximately 2,500W (60 kWh/day).
Can the Antminer S19j be used as a space heater?
Yes — the S19j outputs approximately 11,089 BTU/h, equivalent to a large space heater. D-Central offers space heater conversions for all S19 variants.
What is the difference between the S19j and S19j Pro?
The S19j Pro delivers 104 TH/s at 3,068W (29.5 J/TH) — significantly more hashrate at better efficiency and lower power consumption. The S19j Pro uses more chips per hashboard and benefits from improved manufacturing. If available at similar prices, the S19j Pro is the better choice.
Can I undervolt the S19j?
Yes. The S19j supports undervolting via Braiins OS+, Vnish, and LuxOS. Power capping is the most practical approach — set a target wattage (e.g., 2,500W) and the firmware auto-tunes chip frequencies. This improves efficiency while reducing heat and extending hardware life. See our Undervolting Guide.