Bitmain Antminer S21 Pro

Description

Antminer S21 Pro

The Bitmain Antminer S21 Pro is Bitmain’s flagship SHA-256 Bitcoin miner, built around the next-generation BM1370 ASIC chip. At 234 TH/s and just 15 J/TH, this machine delivers a generational leap in hash density and power efficiency over the S19 series — and a meaningful step up from the standard S21. Whether you are expanding a home mining operation, replacing aging hardware, or building out a dedicated mining room, the S21 Pro puts serious institutional-grade hashrate within reach. Shipped directly from D-Central Technologies in Canada — Bitcoin Mining Hackers since 2016 — every S21 Pro is inspected, tested, and backed by our hands-on technical support team. We do not just sell miners. We repair them, we consult on deployments, and we have the parts inventory to keep them running for years. That full-lifecycle support is what separates buying from D-Central versus rolling the dice on an overseas listing.

Technical Specifications

Specification	Details
Algorithm	SHA-256 (Bitcoin)
Hashrate	234 TH/s
Power Consumption	3,510W (+/- 5%)
Power Efficiency	15 J/TH
ASIC Chip	BM1370 (5nm process)
Hashboards	3 hashboards, 65 chips each (195 total)
Chip Architecture	13 domains per board, 5 ASICs per domain
Input Voltage	220 — 277V AC (requires 240V circuit)
Power Supply	APW17 (included)
Cooling	4x high-speed fans, front-to-back airflow
Noise Level	~76 dB (at 25 C ambient)
Dimensions	450 x 219 x 293 mm (without packaging)
Weight	~20 kg (net)
Network	RJ45 Ethernet (10/100M)
Operating Temp	-20 to 45 C
Storage Temp	-20 to 70 C
Humidity	10 — 90% RH (non-condensing)
Warranty	365 days (manufacturer)
SKU	DC-MINER-S21PRO

The BM1370: Bitmain’s Most Efficient SHA-256 Silicon

The Antminer S21 Pro is built around Bitmain’s BM1370 ASIC chip — a 5nm SHA-256 engine that represents the cutting edge of Bitcoin mining silicon. Each chip hashes at approximately 1.2 TH/s, and with 195 chips across three hashboards organized into 13 domains of 5 ASICs each, the S21 Pro achieves its 234 TH/s rating through raw chip count and architectural efficiency rather than brute-force overclocking. At 15 J/TH, the BM1370 delivers a significant efficiency improvement over the BM1366 used in the standard S21 (17.5 J/TH). That difference compounds across every hour the machine runs. Over a year of continuous operation, the S21 Pro saves roughly 4,380 kWh compared to a standard S21 delivering the same total hashwork — real money in your pocket, especially in regions where electricity is not cheap. The BM1370 is also the chip behind the Bitaxe Gamma, the open-source solo miner. D-Central was among the first to stock BM1370 replacement chips — because we believe in miners being able to repair and modify their own hardware.

S21 Pro vs. S21: Why the Pro Matters

Specification	Antminer S21	Antminer S21 Pro	Advantage
Hashrate	200 TH/s	234 TH/s	+17%
Power	3,500W	3,510W	Nearly identical
Efficiency	17.5 J/TH	15 J/TH	14% more efficient
ASIC Chip	BM1366	BM1370	Next-gen silicon
Heat Output	~11,942 BTU/hr	~11,976 BTU/hr	Same heat, more hash

The takeaway is simple: the S21 Pro gives you 17% more hashrate at essentially the same power draw and heat output. Same electrical circuit, same cooling requirements, same BTU load on your space — but meaningfully more work done on the Bitcoin network per watt consumed. For operations where rack space and power capacity are fixed, the Pro is the obvious upgrade path.

Cooling and Thermal Design

The S21 Pro uses a four-fan forced-air cooling system arranged in a front-to-back configuration. Air enters through the intake side, passes over the three hashboard heatsink assemblies, and exits through the exhaust fans. Bitmain’s thermal design keeps chip junction temperatures within safe operating range across a wide ambient temperature window of -20 to 45 C — making it well-suited for Canadian climate deployments where cold intake air is free and abundant. At ~76 dB, the S21 Pro is a standard industrial ASIC — this is not a living room appliance. It belongs in a dedicated mining space: garage, basement, workshop, shipping container, or purpose-built mining room. If you need a living-space-friendly alternative, check out our Bitcoin Space Heater line or the Antminer Slim Edition. Dual-Purpose Heating: At 3,510W, the S21 Pro outputs approximately 11,976 BTU/hr of thermal energy — equivalent to a medium-sized portable heater. Canadian miners routinely duct exhaust heat into workshops, garages, and adjacent rooms during winter months, effectively mining Bitcoin while offsetting heating costs. Every watt you spend mining is a watt you did not spend on electric baseboard heat.

Firmware Compatibility

The S21 Pro ships with Bitmain’s stock firmware, which includes:

• Web-based management interface (accessible via local IP)
• Pool configuration for up to three mining pools (primary, secondary, tertiary)
• Real-time hashrate, temperature, and fan speed monitoring
• Auto-frequency adjustment based on thermal conditions
• Network diagnostics and firmware update capability

For advanced operators, the S21 Pro is supported by third-party firmware options including VNish and BraiinsOS, which unlock features such as custom frequency/voltage tuning, auto-tuning algorithms, power capping, and more granular monitoring. Third-party firmware can push efficiency even further or allow you to trade efficiency for maximum hashrate depending on your electricity costs and operational goals. Note: Third-party firmware installation voids the manufacturer warranty. D-Central’s ASIC repair team supports machines running both stock and aftermarket firmware.

What’s Included

Item	Details
Antminer S21 Pro Unit	Complete miner with 3 hashboards, control board, and 4 fans
APW17 Power Supply	12-15V DC output, 267A rated, designed for S21 series
C20-P13 Power Cable	Connects PSU to miner (Antwire cable, included)
Ethernet Cable	Standard RJ45 network cable

You will need: A C19 power cord (minimum 16A) to connect the APW17 to your wall outlet. This is region-specific and not included — use a cord rated for your local voltage and plug standard. A 240V dedicated circuit (20A minimum recommended) is required.

Deployment Compatibility

Requirement	Details
Electrical	240V AC, 20A dedicated circuit minimum (NEMA 6-20 or equivalent). Not compatible with standard 120V / 15A household outlets.
Network	Wired Ethernet (RJ45) to router or switch. DHCP or static IP. No built-in WiFi.
Environment	Dedicated mining space with adequate ventilation. -20 to 45 C ambient. Not suitable for living spaces due to noise (~76 dB).
Airflow	Minimum 12 inches clearance on intake and exhaust sides. Do not obstruct fan openings. Consider ducting for heat recovery.
Mining Pools	Compatible with all major SHA-256 pools: Braiins Pool, Foundry USA, ViaBTC, F2Pool, Ocean, DEMAND, etc.
Rack Mounting	Compatible with standard ASIC mining shelving and rack systems

Frequently Asked Questions

Does the Antminer S21 Pro come with a power supply?

Yes. Every S21 Pro from D-Central ships with the APW17 power supply unit and the C20-P13 Antwire cable that connects the PSU to the miner. You will need to provide your own C19 power cord (minimum 16A rating) to connect the PSU to your wall outlet, as these are region-specific. A 240V dedicated circuit (20A minimum) is required — the S21 Pro cannot run on a standard 120V household outlet.

How does the S21 Pro compare to the standard S21?

The S21 Pro delivers 234 TH/s at 15 J/TH versus the standard S21’s 200 TH/s at 17.5 J/TH. That is 17% more hashrate and 14% better efficiency at essentially the same power draw (~3,510W vs ~3,500W). The Pro uses the newer BM1370 chip instead of the BM1366. In practical terms: same electrical requirements, same heat output, same physical footprint, but significantly more hashrate per watt.

What ASIC chip does the S21 Pro use?

The S21 Pro uses Bitmain’s BM1370 ASIC chip, fabricated on a 5nm process. There are 195 chips total across 3 hashboards (65 chips per board), arranged in 13 domains of 5 ASICs each. This is the same chip used in the open-source Bitaxe Gamma solo miner. D-Central stocks BM1370 replacement chips for repair and DIY projects.

Can I use the S21 Pro as a space heater?

At 3,510W, the S21 Pro outputs approximately 11,976 BTU/hr of heat — comparable to a medium portable heater. Many Canadian miners duct the exhaust into adjacent rooms during winter to offset heating costs. However, at ~76 dB, the S21 Pro is far too loud for living spaces. If you want a purpose-built dual-use mining heater, see our Bitcoin Space Heater line, which uses silenced fans and custom enclosures designed for indoor use.

Does D-Central offer repair support for the S21 Pro?

Yes. D-Central Technologies has been repairing ASIC miners since 2016 and maintains a full inventory of BM1370 chips, hashboards, control boards, and APW17 power supplies for the S21 series. Our ASIC repair service handles everything from chip-level hashboard repair to complete diagnostics and refurbishment. We support machines running both stock Bitmain firmware and aftermarket firmware like VNish and BraiinsOS.

Can I run third-party firmware on the S21 Pro?

Yes. The S21 Pro is supported by VNish and BraiinsOS firmware. These unlock advanced features including auto-tuning, custom frequency/voltage profiles, power capping, and enhanced monitoring dashboards. Third-party firmware can improve efficiency or push hashrate higher depending on your optimization goals. Note that installing aftermarket firmware voids the manufacturer warranty, but D-Central’s repair team supports machines running any firmware.

How loud is the S21 Pro?

The S21 Pro produces approximately 76 dB at 25 C ambient temperature — comparable to a loud vacuum cleaner or a busy street. This is standard for industrial ASIC miners. It requires a dedicated mining space: garage, basement, workshop, shipping container, or purpose-built mining room. It is not suitable for living areas, bedrooms, or offices. For noise-sensitive deployments, consider our Antminer Slim Edition (55-60 dB) or Bitaxe solo miners (near-silent).

Does D-Central ship to the United States and internationally?

Yes. D-Central ships from our facility in Laval, Quebec, Canada to customers across Canada, the United States, and worldwide. All shipments include tracking and insurance. Canadian buyers benefit from faster delivery times and no customs fees. For large orders or hosting inquiries, contact our team directly.

Why Buy from D-Central Technologies

D-Central Technologies is not a reseller with a Shopify store and a Telegram channel. We are Bitcoin Mining Hackers — a Canadian company that has been building, repairing, modifying, and deploying mining hardware since 2016. We created the original Bitaxe Mesh Stand. We developed custom Antminer builds like the Slim Edition and Space Heater line. We stock BM1370 chips because we believe miners should be able to repair their own machines.

When you buy an Antminer S21 Pro from D-Central, you are buying from a team that knows this hardware at the chip level. If something goes wrong, we do not point you to a support ticket queue in Shenzhen — we diagnose and repair it in our workshop in Laval, Quebec. We offer mining consulting, hosting in Quebec, and technical support from people who actually mine Bitcoin.

Every hash counts. Whether you are deploying your first ASIC or scaling up a fleet, D-Central is your full-lifecycle partner — from purchase to deployment to repair to upgrade. We are the North, and we are here to help you decentralize the Bitcoin network, one miner at a time.