Hardware Overview: Bitmain's Antminer S21 XP
An overview of Bitmain's Antminer S21 XP — specs, efficiency, hashcost analysis, and where to buy.
TLDR
- Manufacturer: Bitmain
- Series: Antminer S21
- Release Date: June 17, 2024
- Algorithm: SHA-256 (Bitcoin)
- Cooling: Air-cooled
- Efficiency: 13.5 J/TH
Model
Antminer S21 XP
| Specification | Details |
|---|---|
| Hashrate | 270 TH/s (± ~3%) |
| Power Draw | 3,645W (± ~5%) |
| Efficiency | 13.5 J/TH |
| Voltage | 12V |
| Algorithm | SHA-256 |
| Dimensions | 195 × 290 × 400 mm |
| Weight | 18 kg |
| Release Date | June 17, 2024 |
Live profitability: hashrateindex.com/rigs/bitmain-antminer-s21-xp
Background
The Antminer S21 XP is Bitmain's flagship air-cooled machine in the S21 generation, launching in June 2024 as the most efficient air-cooled ASIC in its lineup at the time. At 13.5 J/TH it sits above the S21 Pro (15.0 J/TH) and the base S21 (17.5 J/TH) in efficiency — delivering 270 TH/s from a single air-cooled unit. For operators who built their infrastructure around air-cooled deployments and want the best available efficiency without moving to hydro or immersion, the S21 XP is the natural top of the Bitmain stack.
Specifications
Hashrate
The S21 XP delivers 270 TH/s — 16 TH/s more than the S21 Pro (245T) and 70 TH/s more than the base S21 (200T), while maintaining an air-cooled form factor identical in chassis dimensions to the broader S21 family.
Efficiency
At 13.5 J/TH, the S21 XP is Bitmain's most efficient air-cooled machine. It represents a 10% efficiency improvement over the S21 Pro (15.0 J/TH) and a 23% improvement over the base S21 (17.5 J/TH).
Efficiency comparison across the S21 generation:
| Model | Efficiency | Hashrate | Cooling |
|---|---|---|---|
| S21 (base) | 17.5 J/TH | 200 TH/s | Air |
| S21 Pro | 15.0 J/TH | 220–245 TH/s | Air |
| S21 XP | 13.5 J/TH | 270 TH/s | Air |
| S21 XP Hydro | 12.0 J/TH | 473 TH/s | Hydro |
Power Draw
The S21 XP draws 3,645W — slightly more than the S21 Pro 245T (3,675W) but delivering meaningfully higher hashrate and better efficiency. Operators running S21 Pro infrastructure can deploy the S21 XP without facility power upgrades.
Cooling
Air-cooled, using Bitmain's standard dual high-speed fan configuration. The S21 XP shares the same chassis dimensions (195 × 290 × 400 mm) as other S21 series machines, making it a direct drop-in upgrade for existing S21 rack deployments.
Hashcost Breakeven Analysis
Hashcost measures the electricity cost to produce 1 PH/day of hashrate. The table below shows hashcost for the S21 XP across a range of electricity prices, benchmarked against the hashprice of $49.00/PH/day around the time of launch in June 2024 (Source: Hashrate Index Roundup, June 24, 2024).
| Model | J/TH | $0.03 | $0.04 | $0.05 | $0.06 | $0.07 | $0.08 | $0.09 |
|---|---|---|---|---|---|---|---|---|
| ↑ Hashprice (Jun 2024) | $49.00 | $49.00 | $49.00 | $49.00 | $49.00 | $49.00 | $49.00 | |
| Antminer S21 XP | 13.5 | $9.72 | $12.96 | $16.20 | $19.44 | $22.68 | $25.92 | $29.16 |
At $49.00/PH/day hashprice, the S21 XP was profitable across the entire power cost range shown at launch — all the way to $0.09/kWh. Breakeven power cost: ~$0.151/kWh.
Note: hashprice fluctuates daily. The table reflects a snapshot at launch — use Hashrate Index's live rig page and calculator for real-time figures.
LuxOS Firmware
The S21 XP is compatible with LuxOS, Luxor's custom ASIC firmware. LuxOS enables operators to run the machine across a range of underclocked and overclocked profiles, with Autotuner identifying the optimal voltage-frequency curve for each individual unit — unlocking additional efficiency gains beyond the stock 13.5 J/TH nameplate.
For operators already running LuxOS on S21 Pro hardware, the S21 XP uses the same firmware workflow and deployment process.
Use Hashrate Index's Bitcoin Mining Profitability Calculator to model S21 XP returns at your specific electricity cost and current hashprice.
How to Buy the Antminer S21 XP
The S21 XP is available on the secondary market at pricing well below its 2024 launch MSRP. Luxor's ASIC Trading Desk sources S21 XP inventory for both single-unit and bulk orders.
For current pricing and availability, contact Luxor's hardware team directly: [email protected]
Final Take
The Antminer S21 XP is the top of Bitmain's air-cooled stack — more hashrate, better efficiency, and a direct rack-compatible upgrade from the S21 Pro. At 13.5 J/TH it sits ahead of the current global fleet average, and with LuxOS support it can be pushed further. For operators looking to maximize efficiency within an air-cooled deployment, the S21 XP is the strongest Bitmain option available.
- Antminer S21 XP — Hashrate Index
- Antminer S21 Pro — Hashrate Index (compare)
- Bitcoin Mining Profitability Calculator
To buy: [email protected]
This content is for informational purposes only and should not be construed as financial, investment, or legal advice. Nothing contained herein constitutes a solicitation or recommendation to buy or sell any financial instrument. There are risks associated with Bitcoin mining and ASIC investments.
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