Antminer S21 for Sale
The Antminer S21 is the Bitmain generation that followed the S19. Every S21 model is rated below 20 J/TH, against roughly 21 to 34 J/TH for most S19 versions, so it turns the same electricity into more hashrate. This page lists every S21 on Endless Mining: the air-cooled S21, S21 Pro and S21 XP, and the hydro-cooled S21 Hyd, S21e Hyd and XP Hyd models.
Air-cooled S21s run on a 220–277 V circuit and push their heat out with fans. Hydro models carry the heat away in liquid coolant, usually need a three-phase 380–415 V supply and a cooling loop, and deliver more terahashes per unit. Listing titles give the hashrate in TH/s and often the power draw in watts: divide the watts by the terahashes to compare the efficiency of two versions.
Listings 9 listings
Prices are in US dollars. Listings in stock come first, then by price.
![[WTS] 2x Lightly USED Antminer S21 XP Hydro (473T) – Like New!](/_next/image?url=https%3A%2F%2Fstorage.googleapis.com%2Fendlessmining-production-media%2F2026%2F06%2F9bab70a7-5084-4ee3-8d32-d791ccc82853-scaled.jpeg&w=3840&q=50)
Questions
What is the difference between the S21, S21 Pro and S21 XP?
They are the same generation tuned for more hashrate and better efficiency. Bitmain rates the S21 at 200 TH/s and 17.5 J/TH, the S21 Pro at 234 TH/s and 15 J/TH, and the S21 XP at 270 TH/s and 13.5 J/TH. The more efficient the model, the more it usually costs.
Should I buy an air-cooled or a hydro S21?
Choose air cooling for a standard air-cooled room or a hosting rack: the miner needs only power and airflow. Choose a Hyd model if you have, or host with, a water-cooling setup: hydro units pack more hashrate into each machine, are far quieter at the rack and usually need three-phase power.
Do you sell used S21 miners?
When sellers list them, yes. Each listing states the miner's condition, and every used unit also appears on the used and refurbished page. On sales by independent sellers, Escrow.com holds your payment until you accept the miner.
How does buying here work?
Prices are in US dollars. Listings from independent sellers are paid through Escrow.com, which holds your payment until you accept the item. Outside the US, Endless Mining ships its own miners internationally (ask for a shipping quote); items from other sellers ship to US addresses only. Sales by Endless Mining are final, except where the law requires a return.