Bitmain Antminer S21 Bitcoin Miner

Brand New Bitmain Antminer S21 The Bitmain Antminer S21 235TH/s is a high-performance Bitcoin ASIC miner engineered for serious mining operations with exceptional power efficiency. Designed around the SHA-256 algorithm, the S21 delivers a massive 235TH/s hashrate while maintaining an impressive 16.5 J/TH efficiency, making it a competitive choice for professional and large-scale Bitcoin mining operations.For miners focused on maximizing Bitcoin profitability while controlling operational costs, the Antminer S21 hits the sweet spot between raw computational power and long-term energy optimization. Because electricity bills have a nasty habit of eating mining profits alive.Key BenefitsMassive 235TH/s SHA-256 mining performanceOptimized 16.5 J/TH power efficiencySupports Bitcoin (BTC) and Bitcoin Cash (BCH) miningIndustrial-grade stability for 24/7 uptimeRJ45 Ethernet connectivity for reliable networkingDesigned for professional mining farms and serious operatorsWide operating temperature range from -20°C to 45°CWhy Choose the Antminer S21 ?The ASIC mining market is flooded with machines promising performance while quietly draining power and profitability. The Antminer S21 avoids that embarrassment entirely. Its combination of ultra-high hashrate and advanced energy efficiency makes it an ideal solution for miners scaling operations in competitive Bitcoin mining environments.Whether you’re upgrading older Antminer units or expanding a commercial mining farm, the S21 provides the computational power needed to remain competitive as network difficulty rises.Ideal ForBitcoin mining farmsIndustrial crypto mining facilitiesProfessional ASIC minersHigh-efficiency BTC mining setupsOperators replacing older-generation AntminersOrder Your Antminer S21 TodayIf your current mining hardware struggles to stay profitable, the Antminer S21 is the upgrade path your operation has been waiting for. High hashrate. Lower energy waste. Serious Bitcoin mining performance without compromise. If unsure where to start on your Bitcoin mining journey, checkout our guide on things to know before purchasing a bitcoin miner in 2026 or book a FREE intro meeting with one of our experts!Comes with  manufacturer warranty.PSU includedNote: Antminer S21 runs on 220-277V voltage, it will not operate on household 110-120V voltageSpecificationsProduct Glance ModelS21 Algorithm | CryptocurrencySHA256 | BTC/BCHHashrate, TH/s235Power on wall @25°C, Watt3878Power efficiency on wall @25°C, J/TH16.5Detailed Characteristics Power supply Power supply AC input voltage, Volt(1-1)220~277Power supply AC input frequency range, Hz50~60Power supply AC input current, Amp20Adapted AC output power requirement, W4000Hardware Configuration Network connection modeRJ45 Ethernet 10/100MMiner size (length*width*height, w/o package),mm(2-1)450*219*293Miner size (length*width*height, with package),mm680*390*450Net weight, kg20Gross weight, kg22Noise@25℃，dBA76Environment requirements Operation temperature,°C-20~45Storage temperature,°C-20~70Operation humidity(non-condensing) , RH10%~90%Operation altitude, m≤2000 S21 Mining Profitability Calculator Frequently Asked Questions Is a power cord included with the miner TBD How much overclocking is possible with Antminer S21 ? TBD I'm not getting the advertised efficiency on stock settings. Is there something wrong with my miner? Mining efficiency is highly dependent on ambient air temperature. If your miner is pulling more power than expected, in most cases it is due to a higher ambient temperature. You can improve mining efficiency by preventing mixing of hot exhaust air with intake air.  Which control board does this miner come with? TBD Does the fans on this miner have rectangular or square connectors? TBD How can I make this quiet for home use? Stock fans on Antminers can be very loud (~75 dB) at full speed. There are however multiple ways to make them quieter. First way to make them quieter is to run them at substantial underclocking. This will significantly reduce the hashrate, but will also reduce fan noise, since the fans don’t have to run at full speed when underclocked. Another way to reduce noise is by replacing stock fans with an inline AC infinity fan. You can learn more about this here. This method allows running the miners on stock hashrates and may even allow some overclocking in many cases. Third way to reduce fan noise is by running the miners in immersion mode. In this method the miners are immersed in vats of mineral oil or dielectric fluid. This significantly improves heat transfer and enables substantial overclocking. Immersion mining however voids all warranty, is more complex to setup and immersion fluid can act as a solvent and damage some mining gear. We believe that this is still an experimental technology reserved for the most technically inclined. We do not recommend immersing Antminers to most customers for this reason. Stock Antminer firmware does not allow much flexibility in terms of overclocking/underclocking , fan control, automated temperature control etc. In most cases you would need aftermarket firmware to enable quieter operation.  Can you ship this directly to my hosting company? Yes, you can either take delivery yourself or ship this to your hosting company by providing their address under the shipping address field on checkout page.  Can you recommend a reputable hosting company? While we do not have our own hosting facility, as a Bitcoin mining hardware vendor, we regularly ship ASIC miners and repair parts to various hosting sites across the US. Here’s a list of some of the companies we’ve worked with:–BSLF Mining–Bounty hunter Mining–Terra Hosting–WilsonMiningThis list is a recommendation and not an endorsement for these hosting companies. Please do your own due diligence, before choosing a colocation host. Will there be any additional tariffs or import duties in addition to the list price? No. We ship all our miners from our Missouri, USA location. As a result, all import duties are paid by us when the miners were imported. The buyer does not owe any additional cost.  Who should I contact if there's a problem with my miner? New Antminers come with ~1 year warranty from Bitmain. Please reach out to Bitmain and apply for repair directly with them.  Does this product have a factory warranty? The product is sold new, unopened with a factory warranty unless otherwise requested by the customer to upgrade to aftermarket firmware. Generally, the manufacturer provides a one-year warranty from the manufactured date. The manufacturer warranty period and limitations can be referenced by going directly to their website. For further information and links please view our blog post on warranty. Is this product covered by Altair Technology’s 14 day Warranty Against Defects? his item is excluded from the Altair Technology’s 14 day warranty. However, the manufacturer does provide a warranty. For more information we recommend referencing the manufacturers most updated policy directly from their website.  What coins can the Antminer S21 mine? The Antminer S21 mines SHA-256 cryptocurrencies including Bitcoin (BTC) and Bitcoin Cash (BCH) How much power does the Antminer S21 use? The miner consumes approximately 3878W under standard operating conditions. Is the Antminer S21 suitable for home mining? Due to its 76dBA noise level and commercial power requirements, it is better suited for dedicated mining environments.