Bitmain Antminer S21+ Hyd (319TH)

319 TH/s SHA-256 at 4,785W and 15 J/TH with hydro (liquid) cooling. ±3 percent hashrate and ±5 percent power tolerance. 50 dB noise from water pump only (no high speed fans). The S21+ Hyd is the same chip platform as the air cooled S21+ (235 TH/s) but with liquid cooling enabling higher power delivery at lower temperatures, unlocking 36 percent more hashrate from the same silicon.

This is the most important specification to verify before purchasing. MM body copy and spec sheet list 100 to 240V single phase. CryptoMinerBros lists 380 to 415V three phase. BT-Miners warns about higher voltage requirements. MM's own Quick Setup section says "Hydro-cooled miners require 380-415V three-phase power." These claims directly contradict each other. At 4,785W on 120V the unit draws approximately 40 amps (impractical). At 240V single phase approximately 20 amps (feasible on a dedicated 30A circuit). At 380V three phase approximately 7.3 amps per phase (standard industrial). Contact MillionMiner to confirm the actual voltage requirement before planning electrical infrastructure or making a purchase decision.

Closed loop water or water glycol system. Components: circulation pump, heat exchanger (dry cooler, CDU, or radiator), supply and return plumbing, quick disconnect fittings, coolant. No dielectric fluid (unlike immersion). Flow rate typically 8 to 10 L/min for Antminer hydro units. Inlet coolant temperature 20 to 40 degrees Celsius. For a single miner: approximately $1,000 to $3,000 in cooling infrastructure. For operators already running Bitmain hydro hardware, the S21+ Hyd adds to existing cooling loops with standard quick disconnect connections.

S21+ Hyd at 319 TH/s, 4,785W, 15 J/TH, 50 dB, $3,137 (hydro). S21 PRO at 234 TH/s, 3,510W, 15 J/TH, 75 dB, $3,083 (air). Same efficiency per terahash. The Hyd produces 36 percent more hashrate for $54 more CapEx. The Hyd is 25 dB quieter. The Hyd requires water cooling infrastructure. The PRO plugs directly into a 220V circuit. If you have or will build hydro cooling, the S21+ Hyd produces 40 percent more daily profit ($2.63 versus $1.87). If you want zero infrastructure complexity, the S21 PRO is simpler.

S23 Hyd at 580 TH/s, 5,510W, 9.5 J/TH, $14,299 (flagship). S21+ Hyd at 319 TH/s, 4,785W, 15 J/TH, $3,137 (this product). The S23 Hyd is 37 percent more efficient, produces 82 percent more hashrate, and generates +$6.47 daily versus +$2.63. But the S23 Hyd costs $14,299 (4.6x more) and requires 380V+ three phase. The S21+ Hyd is the budget entry to Bitmain hydro mining. Four S21+ Hyd units (1,276 TH/s total at $12,548) deliver more total hashrate than one S23 Hyd (580 TH/s at $14,299) for less total cost but at worse fleet efficiency (15 versus 9.5 J/TH).

S21 XP Hydro at 473 TH/s, 5,676W, 12 J/TH, $6,899. S21+ Hyd at 319 TH/s, 4,785W, 15 J/TH, $3,137. The XP Hydro delivers 48 percent more hashrate at 20 percent better efficiency for 120 percent more cost. The XP Hydro produces +$3.01 daily versus +$2.63 for the S21+ Hyd. The $3,762 price premium pays for itself in approximately 9,900 days through the $0.38 daily profit difference. By pure ROI math, two S21+ Hyd units ($6,274) outproduce one S21 XP Hydro ($6,899): 638 TH/s at $5.26 daily versus 473 TH/s at $3.01 daily. The S21+ Hyd fleet wins on hashrate per dollar and daily profit per dollar.

Yes. MillionMiner calculator at $0.08 per kWh: +$2.63 daily ($11.82 revenue minus $9.19 electricity). Monthly: +$78.90. At $3,137 acquisition: payback approximately 40 days. At $0.07 per kWh: +$3.78 daily, payback approximately 28 days. At $0.05 per kWh: +$6.08 daily, payback approximately 17 days. Profitable at any electricity rate below approximately $0.10 per kWh at April 2026 conditions.

50 dB. Hydro cooling eliminates high speed fans. The only noise source is the water pump and residual electronics. 50 dB is comparable to a quiet conversation or moderate rainfall. 25 dB below air cooled equivalents (75 dB). For high density data centers, the 50 dB floor enables co-location in spaces where 75 dB air cooled miners would exceed noise regulations.

Dimensions vary across sources: MM lists 410 x 170 x 209 mm. Mining Now and CryptoMinerBros list 339 x 173 x 207 mm. Weight varies: MM 13.5 kg, CryptoMinerBros 15 kg, Mining Now 13.8 kg. Regardless of which source is accurate, the S21+ Hyd is compact and light for a hydro miner (the S19 XP+ Hyd 3U weighs 50 kg). Verify actual dimensions with MillionMiner for rack planning.

MM lists 5 to 40 degrees Celsius at 10 to 90 percent humidity. CryptoMinerBros lists 20 to 50 degrees Celsius (inlet coolant temperature range, not ambient). LeedMiner lists 5 to 40 degrees Celsius. The 5 to 40 degree range refers to inlet coolant temperature in hydro miners, not ambient room temperature. The hydro cooling system isolates the miner from ambient conditions, which is one of liquid cooling's advantages: consistent chip temperatures regardless of facility ambient.

All SHA-256 proof of work cryptocurrencies. Bitcoin (BTC) primary. Bitcoin Cash (BCH), Bitcoin SV (BSV), eCash (XEC), and other SHA-256 chains. Same coin compatibility as every Bitmain S21 series miner regardless of cooling type.

Yes per MM box contents. The S21+ Hyd has a built in PSU. Connect directly to the appropriate voltage outlet (verify 100-240V or 380V+ requirement). No external PSU to source.

BraiinsOS+ supports S21 series Antminer hardware. Hydro models have historically been compatible with Braiins firmware. Verify current BraiinsOS+ S21+ Hyd support on Braiins documentation. If supported, autotuning can push efficiency below the stock 15 J/TH. The Antminer firmware ecosystem is the most developed in the ASIC industry.

Yes. MillionMiner hosting facilities include hydro infrastructure. At $0.07 per kWh hosted: +$3.78 daily. Hosting eliminates the need for the buyer to build water cooling infrastructure, which is the primary barrier to hydro miner deployment. For buyers who want hydro mining economics without building cooling systems, hosted deployment is the practical solution.

If the S21+ Hyd genuinely runs on 100 to 240V single phase (which requires verification), then yes: Bitmain's newer hydro miners (S23 Hyd, S21e XP Hydro) all require 380V+ three phase. No current Bitmain hydro model under development has announced single phase compatibility. Once S21 generation inventory depletes, operators needing single phase hydro would have no current Bitmain option. This dynamic makes the S21+ Hyd inventory potentially finite and unreplaceable for operators in single phase facilities.

Periodic coolant system maintenance. Check coolant levels and quality quarterly. Inspect quick disconnect fittings for leaks. Monitor flow rate through the miner. Clean or replace coolant filter if present. Monitor hashrate through Antminer web interface. Hydro miners generally require less chip level maintenance than air cooled (no dust accumulation on chips, more consistent temperatures). Water system maintenance replaces fan maintenance.

365 day Bitmain manufacturer warranty per ASIC Marketplace and CryptoMinerBros. Covers manufacturing defects and hardware failures under normal operating conditions. Among the longest warranties in the ASIC industry. Warranty may be voided by improper coolant use, operating outside specified temperature range, or non Bitmain firmware modification.

Water or water glycol mix. Standard water cooling coolant. No special dielectric fluid required (unlike immersion cooling). Water glycol mix recommended for facilities where coolant temperature may drop below freezing (outdoor dry coolers in cold climates). Typical glycol concentration: 20 to 30 percent propylene glycol. Distilled or deionized water preferred to prevent mineral buildup in the internal cold plate channels.

The S21+ Hyd is the most affordable Bitmain hydro miner in stock at $3,137 with strong daily margins (+$2.63 at $0.08 per kWh) and approximately 40 day payback. Buy if: you have existing hydro cooling infrastructure and want to add capacity at minimum CapEx, you want 50 dB operation versus 75 dB on air cooled alternatives, or (pending voltage verification) you need hydro mining on single phase power. Before purchasing: verify the voltage requirement with MillionMiner (100-240V single phase or 380V+ three phase). Verify whether you have or can build water cooling infrastructure. If you want maximum hydro efficiency and have three phase power, consider the S23 Hyd (9.5 J/TH, $14,299). If you want zero infrastructure complexity, consider the air cooled S21 PRO ($3,083) or A3 Pro Air ($4,490).

Within Bitmain hydro upgrades: S21 XP Hydro (473 TH/s, 12 J/TH, $6,899), S21 XP+ Hyd (500 TH/s, 11 J/TH, $9,500), S23 Hyd (580 TH/s, 9.5 J/TH, $14,299), S23 Hyd 3U (1.16 PH, 9.5 J/TH, $32,379). Air cooled alternatives: S21 PRO (234 TH/s, 15 J/TH, $3,083), S21 XP (270 TH/s, 13.5 J/TH, $4,051), Bitdeer A3 Pro Air (290 TH/s, 12.5 J/TH, $4,490). Hydro infrastructure: MillionMiner stocks hydro radiators, racks, and mining containers for complete hydro facility builds.