The Bitmain Antminer S19a is a mid-generation refresh of the S19 platform, featuring the improved BM1398AC chip variant that delivered higher efficiency through better silicon binning and optimized power delivery. Delivering 96 TH/s at approximately 3,344W, the S19a achieved an efficiency of approximately 34.8 J/TH — comparable to the base S19 but with marginally higher hashrate. Released in 2021, the S19a represented Bitmain’s ongoing refinement of the S19 platform as they extended its production lifecycle.
The “a” designation indicates an architectural revision: the S19a uses the BM1398AC chip variant (as opposed to the BM1398BB in the original S19 and S19 Pro), with a redesigned hashboard layout featuring 100 chips per board rather than the S19’s 76 or the S19 Pro’s 114. This revised chip configuration aimed to balance manufacturing cost, hashrate output, and power efficiency.
In 2026, the S19a occupies a similar market position to other S19-family variants. It is available at low secondary market prices and provides competitive hashrate for its cost. Its performance is comparable to the base S19, and it shares the same chassis, PSU, and firmware compatibility. For budget mining, space heater conversions, and home mining setups, the S19a is a solid choice. D-Central Technologies provides full repair and conversion services for all S19 variants including the S19a.
Antminer S19a Full Specifications
| Specification | Details |
|---|---|
| Manufacturer | Bitmain |
| Model | Antminer S19a |
| Release Date | 2021 |
| Algorithm | SHA-256 |
| Hashrate | 96 TH/s (±5%) |
| Power Consumption | 3,344W (±5%) |
| Efficiency | 34.8 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 | BM1398AC (7nm) |
| Chips per Hashboard | 100 |
| Number of Hashboards | 3 |
| Total Chip Count | 300 |
| Power Supply | Integrated APW12 PSU |
Performance Analysis
At 34.8 J/TH, the S19a is closely comparable to the base S19 (34.2 J/TH), within the margin of variance. It is less efficient than the S19 Pro (29.5 J/TH) but outperforms the S19j (36.1 J/TH) and T19 (37.5 J/TH). Against the S21 (17.5 J/TH), the S19a uses approximately twice the energy per terahash.
The S19a’s 96 TH/s hashrate is marginally higher than the base S19’s 95 TH/s, offering a very slight advantage in hash output. The slightly higher power consumption (3,344W vs 3,250W) mostly offsets this gain in terms of net efficiency. In practice, the S19a performs very similarly to the base S19.
Daily and Monthly Power Costs
| Electricity Rate | Daily Power Cost | Monthly Power Cost | Viability |
|---|---|---|---|
| $0.05/kWh | $4.01 | $120 | Profitable — solid margins at cheap electricity rates |
| $0.08/kWh | $6.42 | $193 | Marginally profitable — monitor difficulty and BTC price |
| $0.10/kWh | $8.03 | $241 | Breakeven — best as a dual-purpose space heater |
| $0.12/kWh | $9.63 | $289 | Unprofitable — space heater conversion or undervolting needed |
Heat Output
The S19a produces approximately 11,410 BTU/h of heat (3,344W × 3.412 BTU/W). This is slightly more than the standard S19 (~11,089 BTU/h) due to the marginally higher power consumption, and represents powerful heating capacity. For Canadian and northern-climate miners, this heat output makes the S19a an excellent candidate for space heater conversion.
Compatible Firmware
| Firmware | Compatibility | Key Features |
|---|---|---|
| Stock (Bitmain) | Full support | Default firmware, basic configuration |
| Braiins OS+ | Supported | Autotuning, Stratum V2, power capping |
| Vnish | Supported | Custom profiles, overclocking, immersion mode |
| LuxOS | Supported | Curtailment, fleet management |
For guides: Braiins OS+ | Vnish | LuxOS | Firmware Update Guide
Best Use Cases in 2026
Budget Mining: The S19a offers comparable performance to the base S19 and is often available at competitive secondary market prices. For miners with electricity under $0.08/kWh, the S19a delivers strong value per dollar invested.
Space Heater Conversion: At ~11,400 BTU/h, the S19a provides significant heating capacity. D-Central offers Bitcoin Space Heater conversions for all S19 variants. See our Space Heater Assembly Guide for setup details.
Home Mining: The S19a uses the same proven chassis, APW12 PSU, and firmware ecosystem as the rest of the S19 family. At 75 dB, it requires a dedicated space (garage, basement, utility room) but is manageable with proper placement.
Undervolting: The BM1398AC chips in the S19a respond well to undervolting via Braiins OS+ or Vnish. Power-capping to ~2,600W while maintaining 75-85 TH/s can push efficiency below 33 J/TH. See our Complete Undervolting Guide.
Common Issues & Repair
The S19a shares its reliability profile with the broader S19 family, with some considerations specific to the BM1398AC chip:
- Hashboard chip failures: BM1398AC chips can fail over time, causing reduced hashrate or missing chains. The 100-chip-per-board configuration means a single chip failure has a slightly smaller proportional impact than on the 76-chip S19 boards. See our Chain X Only Fix Guide.
- APW12 PSU issues: The integrated power supply can develop capacitor degradation, especially under sustained high loads. See our APW12 PSU Repair Guide.
- Temperature management: The slightly higher power consumption of the S19a (3,344W vs 3,250W) generates marginally more heat, making proper ventilation especially important. See our Temp Too High Fix Guide.
- EEPROM errors: Control board EEPROM corruption can prevent proper hashboard detection. See our EEPROM Error Fix Guide.
D-Central offers professional Antminer S19a Repair services from our Canadian workshop. See our ASIC Repair Cost Estimator for pricing.
D-Central Services for the Antminer S19a
- Repair: Hashboard, PSU, control board repair — Antminer S19a Repair
- PSU Service: APW12 diagnostics and repair — APW12 PSU Guide
- Space Heater Conversion: Home heating setup — Bitcoin Space Heaters
- Undervolting: Optimize power — Undervolting Guide
- Replacement Parts: Hashboards, fans, PSU — Shop Parts
- Repair Cost Estimate: ASIC Repair Cost Estimator
Frequently Asked Questions
Is the Antminer S19a still profitable in 2026?
Yes, the S19a is profitable at electricity rates below $0.08/kWh. Performance is very similar to the base S19. With undervolting via aftermarket firmware, profitability extends to higher electricity rates. As a space heater during heating season, the S19a is cost-effective at any electricity rate.
How much electricity does the Antminer S19a use per day?
The S19a consumes approximately 3,344W continuously, translating to 80.3 kWh per day or about 2,408 kWh per month. At $0.10/kWh, that is $8.03/day or $241/month. Undervolting can reduce consumption to approximately 2,600W (62.4 kWh/day).
Can the Antminer S19a be used as a space heater?
Yes — the S19a outputs approximately 11,410 BTU/h, making it an excellent heater. D-Central offers space heater conversions for all S19 variants.
What is the difference between the S19a and S19?
The S19a uses the newer BM1398AC chip variant (vs BM1398BB in the S19), with 100 chips per hashboard (vs 76). The S19a delivers 96 TH/s at 3,344W (34.8 J/TH) compared to the S19‘s 95 TH/s at 3,250W (34.2 J/TH). Performance is very similar — the S19a trades slightly higher power consumption for marginally more hashrate.
What chip does the S19a use?
The S19a uses the BM1398AC chip — an optimized variant of the BM1398 family. The “AC” revision features improved manufacturing characteristics compared to the “BB” variant used in the original S19 and S19 Pro. Parts for S19a repair (including BM1398AC chips) are available through D-Central’s parts catalog.