Bitmain Antminer S21 XP

Description

Bitmain Antminer S21 XP — 270 TH/s of Raw SHA-256 Power at 13.5 J/TH

The Antminer S21 XP is Bitmain’s most efficient air-cooled Bitcoin miner to date. At 270 TH/s with a wall efficiency of 13.5 J/TH, it delivers a 35% efficiency improvement over the original S21 and nearly doubles its hashrate — all on standard single-phase 220-277V power. This is the machine that redefines what is possible with air cooling. Built around the BM1370 ASIC chip on a 3nm process node, the S21 XP packs three hashboards with approximately 270 chips total, each running at optimized low frequencies for maximum joules-per-terahash performance. The result: more hashrate per watt than any previous air-cooled Antminer generation. Tinned copper bus bars replace traditional PCB traces for cleaner power delivery, aluminum-backed hashboards with bolt-on heatsinks ensure long-term thermal reliability, and four oversized 140mm fans push serious airflow through the wide-body chassis. Whether you are expanding a fleet, upgrading aging S19-era hardware, or building a new operation from scratch, the S21 XP is the air-cooled benchmark. And when you buy it from D-Central Technologies — Canada’s Bitcoin Mining Hackers since 2016 — you get more than a miner. You get a partner with a full-service ASIC repair facility, deep S21-series expertise, and a team that has serviced 2,500+ mining machines at the component level.

Technical Specifications

Specification	Details
Model	Bitmain Antminer S21 XP
Algorithm	SHA-256 (Bitcoin, Bitcoin Cash, and other SHA-256 coins)
Hashrate	270 TH/s
Power Consumption	3,645W (±5%)
Efficiency	13.5 J/TH
ASIC Chip	BM1370 (3nm process node)
Hashboards	3
Chips per Hashboard	~91
Input Voltage	220–277V AC (single-phase)
Cooling	4 x 140mm high-speed fans (air-cooled)
Noise Level	76 dB
Dimensions	449 x 219 x 293 mm (17.7 x 8.6 x 11.5 in)
Weight	18.7 kg (41.2 lbs)
Network Connection	RJ45 Ethernet (Gigabit)
Control Board	Amlogic A113D with detachable 0.91″ OLED display
Operating Temperature	-20°C to 45°C (-4°F to 113°F)
Storage Temperature	-20°C to 70°C (-4°F to 158°F)
Humidity	10–90% (non-condensing)
PSU	Integrated (built-in power supply)

Performance — 270 TH/s on Air, No Compromises

The S21 XP delivers 270 terahashes per second — more hashrate than two Antminer S21 units combined, in a single machine. At 13.5 J/TH, it achieves a 35% efficiency improvement over the original S21 (17.5 J/TH) and a 12% improvement over the S21 Pro (15.5 J/TH). In practice, that means substantially more Bitcoin mined per kilowatt-hour consumed. This is not just an incremental refresh. The BM1370 chip running at optimized low frequencies produces more hash per watt than any previous Bitmain air-cooled design. Each chip operates at approximately 1 TH/s, with tight voltage regulation across all three hashboards ensuring consistent, stable operation under load. The tinned copper bus bars that replace traditional PCB power traces reduce resistive losses and improve long-term reliability — a design choice borrowed from industrial power electronics. For Canadian miners running on Quebec’s low-cost hydroelectricity or Alberta’s competitive industrial rates, the S21 XP’s efficiency translates directly into longer profitable runway as difficulty rises. At $0.06 CAD/kWh, this machine moves the profitability needle in a way that older hardware simply cannot match.

Efficiency — 13.5 J/TH Changes the Economics

Efficiency is everything in Bitcoin mining. The S21 XP’s 13.5 J/TH rating means it produces each terahash of computation using 37% less energy than the S19 XP Hyd (21.5 J/TH) and 23% less than the original S21. Over the lifetime of the machine, those savings compound into thousands of dollars in reduced electricity costs.

Model	Hashrate	Power	Efficiency
Antminer S19 XP	140 TH/s	3,010W	21.5 J/TH
Antminer S21	200 TH/s	3,500W	17.5 J/TH
Antminer S21 Pro	234 TH/s	3,510W	15.0 J/TH
Antminer S21 XP	270 TH/s	3,645W	13.5 J/TH
Antminer S21 XP Hyd	473 TH/s	5,676W	12.0 J/TH

The S21 XP sits at the sweet spot: best-in-class air-cooled efficiency without the complexity of hydro or immersion cooling infrastructure. Plug it into a 220-240V circuit, connect Ethernet, point it at your pool, and it is mining at peak efficiency within minutes.

Build Quality — Engineered for the Long Haul

Bitmain refined the physical design across the entire S21 XP platform:

• Aluminum-backed hashboards with bolt-on heatsinks — Better thermal coupling than adhesive-mounted solutions. Each hashboard is mechanically secured for vibration resistance during shipping and operation, reducing the risk of chip delamination that plagued earlier Antminer generations.
• Tinned copper bus bars — Power delivery through bus bars instead of PCB traces means lower impedance, less heat generation at the power delivery stage, and improved long-term reliability under continuous high-current operation.
• Four 140mm fans — Larger than previous Antminer fan designs, these move more air at lower RPM, improving the noise-to-airflow ratio. The 4-pin connectors support PWM speed control for temperature-responsive operation.
• Detachable OLED display — The 0.91″ screen on the control board panel shows miner status (hashrate, temperature, fan speed, IP address) at a glance without needing to log into the web interface or SSH into the machine. A small feature that saves time when managing multiple units.
• Wide-body chassis — The S21 XP retains the wider form factor introduced with the S21 Pro (449mm x 219mm x 293mm), providing more internal volume for airflow and reducing thermal hotspots across the hashboards.
• Integrated PSU — The built-in power supply eliminates the need for a separate APW unit, simplifying deployment and reducing cable clutter. A single C20-P13 power cord connects the miner to your PDU or wall outlet.

Firmware Compatibility — Stock and Third-Party

The S21 XP ships with Bitmain stock firmware, which provides solid baseline performance with automatic frequency and voltage management. For operators who want more control, the S21 XP is compatible with major third-party firmware options:

• Braiins OS+ — Autotuning for per-chip optimization, Stratum V2 support for improved pool communication, and granular power limiting. Ideal for operators who want to set a wattage ceiling and let the firmware maximize hashrate within that budget.
• VNISH — Advanced overclocking and underclocking profiles, immersion mode support, per-hashboard tuning, and detailed diagnostic reporting. VNISH explicitly supports the S21 XP model.
• LuxOS — Firmware with fleet management features, curtailment scheduling, and detailed telemetry for large-scale deployments.

Note: If your S21 XP ships with stock Bitmain firmware dated March 2024 or later, you may need to downgrade to an earlier stock version before flashing third-party firmware. D-Central’s firmware download center hosts verified firmware images, and our repair team can assist with firmware transitions if needed.

What’s Included

• Bitmain Antminer S21 XP miner unit with integrated PSU
• C20-P13 power cord (1.2m)
• Quick start guide
• Warranty documentation (365-day Bitmain warranty)

You will need: A 220-240V outlet (30A circuit recommended), Ethernet cable (Cat5e or better), and an internet-connected router or switch. The S21 XP does not support WiFi — wired Ethernet only.

Compatibility & Installation Notes

Requirement	Details
Electrical	220–277V AC, single-phase, 30A dedicated circuit recommended
Plug/Connector	C20 inlet (included C20-P13 cord fits standard C19 PDUs)
Network	Wired Ethernet (RJ45) — no WiFi
Ventilation	Minimum 12 inches of clear space in front of and behind the unit. Exhaust air reaches 50-60°C — ducting recommended for indoor installations.
Noise	76 dB — equivalent to a vacuum cleaner. Not suitable for living spaces without sound isolation. Garage, basement, or dedicated mining room recommended.
Mining Pools	Compatible with all major Stratum V1 and V2 pools (Ocean, Braiins, Foundry, F2Pool, ViaBTC, Luxor, etc.)
Duct Adapters	D-Central’s S21 XP to 8″ Round Vent Duct Shroud Adapter — 3D printed, designed specifically for the S21 XP wide-body chassis
Operating System	Web-based management interface accessible from any browser on the same network

Canadian Home Mining Tip: The S21 XP draws approximately 16-17A at 220V. In Canada, a NEMA 6-30R outlet on a 30A breaker is the standard setup. If you are adding a 240V circuit, hire a licensed electrician. For ducting the exhaust heat into your home heating system during Canadian winters, check our 8-inch duct shroud adapter designed specifically for the S21 XP.

Frequently Asked Questions

Can I run the Antminer S21 XP on 110V / 120V power?

No. The S21 XP requires 220-277V single-phase power. It will not operate on standard North American 110-120V outlets. You need a dedicated 240V circuit — typically a NEMA 6-30R outlet wired to a 30A breaker. This is the same type of outlet used for electric dryers and ovens. A licensed electrician can install one for $200-500 CAD depending on your panel and wiring distance. If you want a miner that runs on 120V, check out D-Central’s Antminer Slim Edition — custom-built for standard household power.

Does the S21 XP come with a power supply?

Yes. The S21 XP has an integrated power supply — the PSU is built into the miner chassis. Unlike older Antminer models (S9, S17, S19 series) that required a separate APW power supply unit, the S21 XP connects directly to your power source with a single C20-P13 cord (included). No separate PSU purchase needed.

How loud is the Antminer S21 XP?

The S21 XP operates at approximately 76 dB — comparable to a vacuum cleaner or a loud conversation. It is not suitable for living areas, bedrooms, or offices without sound isolation. Most home miners run the S21 XP in a garage, basement, or dedicated mining closet with proper ventilation. For noise reduction strategies, see our guide on reducing ASIC miner noise. D-Central also sells duct shroud adapters that channel exhaust through ductwork, reducing perceived noise in adjacent rooms.

What is the electricity cost to run the S21 XP?

At 3,645W continuous draw, the S21 XP consumes approximately 87.5 kWh per day. At Quebec’s residential rate of approximately $0.073 CAD/kWh, that is roughly $6.39 CAD/day or $192 CAD/month. At Alberta’s average of approximately $0.12 CAD/kWh, it is about $10.50 CAD/day or $315 CAD/month. At Ontario’s off-peak rate of $0.087 CAD/kWh, roughly $7.61 CAD/day or $228 CAD/month. Your actual profitability depends on current Bitcoin price, network difficulty, pool fees, and your specific electricity rate. Always run the numbers before deploying.

How does the S21 XP compare to the original S21?

The S21 XP delivers 270 TH/s at 13.5 J/TH compared to the original S21’s 200 TH/s at 17.5 J/TH. That is 35% more hashrate and 23% better efficiency — a generational improvement. The S21 XP uses the newer BM1370 chip (3nm) versus the S21’s BM1368 (5nm), has a wider chassis with better airflow, an integrated PSU (no separate power supply needed), a detachable OLED display, and upgraded power delivery with tinned copper bus bars. If you are deciding between the two, the S21 XP is the clear upgrade for any operator focused on long-term efficiency.

Can I use the S21 XP as a space heater?

Absolutely. The S21 XP outputs approximately 3,645W of heat — equivalent to a large portable electric heater. Canadian miners commonly duct the exhaust into their home heating system during winter months, offsetting heating costs while mining Bitcoin. D-Central sells 8-inch duct shroud adapters designed specifically for the S21 XP’s wide-body chassis. During summer, you will need to vent the heat outdoors. For purpose-built dual-use solutions, check out D-Central’s Bitcoin Space Heater collection.

Is the S21 XP compatible with third-party firmware?

Yes. The S21 XP is supported by Braiins OS+, VNISH, and LuxOS — the three major third-party Antminer firmware options. Braiins OS+ offers autotuning and Stratum V2 support. VNISH provides advanced overclocking/underclocking and detailed diagnostics. LuxOS adds fleet management and curtailment scheduling. Note: units shipping with stock firmware dated March 2024 or later may require a firmware downgrade before third-party installation. Visit D-Central’s firmware download center for verified images and guides, or read our firmware compatibility matrix for full details.

What happens if my S21 XP needs repair?

D-Central Technologies operates one of North America’s leading ASIC repair facilities in Laval, Quebec. Our technicians repair Antminer hashboards at the component level — individual BM1370 chip replacement, bus bar rework, control board diagnostics, and fan replacement. We have deep experience with the entire S21 series. This is the advantage of buying from a full-service mining company: the same team that sold you the miner can repair it. No shipping overseas, no weeks-long turnaround with anonymous third parties. Contact us for a repair quote.

Why Buy from D-Central Technologies

D-Central is not a reseller with a Shopify store and a shipping label. We are Canada’s Bitcoin Mining Hackers — a full-service mining company that has been building, repairing, modifying, and deploying mining hardware since 2016. When you buy the Antminer S21 XP from D-Central, here is what stands behind your purchase:

• Component-level ASIC repair — Our Laval, Quebec facility has serviced 2,500+ mining machines. If your S21 XP ever needs a hashboard repair, BM1370 chip replacement, or control board diagnostic, the expertise is already here. We repair what we sell.
• S21-series expertise — We stock the Antminer S21, S21 XP, BM1370 replacement chips, S21 replacement hashboards, APW17 power supplies, and custom-designed duct adapters. The full ecosystem, not just the flagship unit.
• Ships from Canada — Canadian pricing in CAD, fast domestic shipping, no cross-border surprises. Bilingual support in English and French from our team in Laval, Quebec.
• Firmware and setup support — Our firmware download center hosts verified stock and third-party firmware images. Our blog covers S21 reviews, firmware flashing guides, undervolting tutorials, and home mining setup guides.
• Pioneer in the mining space — From creating the original Bitaxe Mesh Stand to developing custom Antminer modifications (Slim Edition, Loki Edition, Pivotal Edition) to building Canada’s deepest open-source miner catalog, D-Central has been pushing the boundaries of accessible Bitcoin mining for nearly a decade.

Every hash counts. Every watt matters. And when the machine that produces them is backed by a team of miners, builders, and repair technicians who have been in the trenches since 2016 — that is the D-Central difference. D-Central Technologies — Decentralizing every layer of Bitcoin mining. From our facility in Laval, Quebec to your mining operation, wherever it may be. Shop the full catalog | ASIC Repair Services | Contact Us