Bitmain Antminer S21 Imm. dual-mode reference
Official Antminer S21 Imm. version 10 reference covering NEM 239 TH/s and HEM 301 TH/s modes with exact three-phase and full-immersion requirements.
Quick answer
The Bitmain Antminer S21 Imm. dual-mode reference is a Bitcoin miner rated about 239-301 TH/s at roughly 3,824 W (about 16 J/TH).
Full Specifications
| Model | Bitmain Antminer S21 Imm. dual-mode reference |
|---|---|
| Model Number | Antminer S21 Imm. version 10 |
| Manufacturer | Bitmain |
| Algorithm | SHA-256 |
| Coins Mined | Bitcoin (BTC) |
| Hashrate | 239-301 TH/s |
| Power Consumption | 3,824-5,569 W |
| Cooling | Immersion |
| Voltage Range | 380-415 V AC three phase; 50-60 Hz; 12 A max |
| Operating Temperature | 30-55 C inlet oil |
| Dimensions | 293 x 236 x 364 mm including handle |
| Weight | 17.15 kg net |
| Interface | RJ45 Ethernet 10/100M |
| Status | OEM support reference |
Official dual-mode immersion reference: Bitmain documents the Antminer S21 Imm., version 10, in two operating modes at 30°C inlet oil: NEM at 239 TH/s, 3,824 W, and 16 J/TH; HEM at 301 TH/s, 5,569 W, and 18.5 J/TH.
| Official mode | Hashrate | Wall power | Efficiency |
|---|---|---|---|
| NEM | 239 TH/s | 3,824 W | 16 J/TH |
| HEM | 301 TH/s | 5,569 W | 18.5 J/TH |
Actual hashrate is ±3%; wall power and efficiency are ±5%. The former 227T record is not part of the current official matrix.
Three-phase electrical and immersion gate
The official input is 380–415 V AC three phase, 50–60 Hz, with 12 A maximum current. Inlet oil must be 30–55°C and flow is 1 m³/h. The product manual states that the miner must be fully immersed while running.
Do not operate this unit in air. Validate dielectric fluid compatibility, tank design, circulation, filtration, heat rejection, grounding, protection, leak/spill controls, fire strategy, and emergency isolation.
Physical and environmental reference
The server including its 44 mm handle is 293 × 236 × 364 mm and 17.15 kg net. Packaged dimensions are 570 × 316 × 430 mm and gross weight is 20.45 kg. Network access is RJ45 Ethernet. Storage is −20–70°C; altitude is up to 2,000 m with temperature derating above 900 m.
Exact-name boundary
S21 Imm. and S21 XP Imm. are separate identities. An immersion chassis does not prove shared power modes, PSU, controller, firmware, fluid requirements, or recovery procedures.
Firmware, recovery, and repair
- Identify the exact label, version, board, and installed firmware.
- Use only the exact current manufacturer support entry.
- For no boot, fluid contamination, leakage, corrosion, instability, or electrical and thermal symptoms, request Antminer diagnosis.
Primary sources: Bitmain S21 Imm. specification and official manual/support hub. Reviewed August 27, 2026.