Performance and Efficiency : New vs. Used Miners
Brand-new ASICs run on the latest chips, delivering far greater hashing power and superior efficiency than older models. For example, a Bitmain Antminer S21+ (2025 model) achieves around 216 TH/s while drawing approximately 3564 W. In contrast, an Antminer S19 (2020) manages about 95 TH/s at 3250 W. Practically speaking, the S21+ hashes over twice as fast while using just a slightly higher power draw. This means the modern machine gets much more work per watt. The S21+ operates at around 16.5 J/TH (joules per terahash), while the older S19 runs at about 34.5 J/TH. In other words, the S21+ delivers roughly double the efficiency, producing far more hash for the same amount of electricity.
This efficiency gap significantly impacts mining profitability, especially in regions with high power costs. When electricity is expensive, the S21+’s lower joules-per-hash offers a clear advantage. Older models like the S19 burn more energy for every bitcoin mined, increasing operational costs. As Bitdeer notes, “older models tend to consume more electricity, thus consider energy costs while computing ROI.” Based on our experience, an older rig often needs access to low-cost power to remain marginally profitable.
However, used miners can still be viable under the right conditions. We’ve advised some clients to start small with second-hand S19 units, which often allow for a quicker break-even point thanks to their low upfront cost. That said, our larger clients generally upgrade to the latest models like the S21+ 216T to stay competitive as mining difficulty continues to rise.
| Aspect | Brand-new Antminer S21+ (2025) | Used Antminer S19 (2020) |
|---|---|---|
| Hashing Power (TH/s) | 216 TH/s | 95 TH/s |
| Power Draw (W) | 3564 W | 3250 W |
| Efficiency (J/TH) | 16.5 J/TH | 34.5 J/TH |
| Hash Rate vs Power Use | Over twice the hashing power with slightly higher power draw | Lower hash rate for nearly the same power |
| Efficiency Comparison | Roughly double the efficiency, more hash per unit of electricity | Much lower efficiency, higher energy cost per hash |
| Impact on Profitability | Lower Joules-per-Hash means higher profitability, especially with expensive power | Requires cheap electricity to remain marginally profitable |
| Practical Use Cases | Ideal for high-efficiency mining in competitive markets | Viable for starting small due to low upfront cost |
| Customer Preference | Larger clients generally upgrade to S21+ to stay competitive as mining difficulty rises | Some clients start with used S19 units to reduce initial investment |
Note: This table summarizes the performance and efficiency of the Antminer S21+ versus the S19, along with mining profitability considerations.
Power Consumption : New vs. Used Miners
Because new ASICs like the Antminer S21 XP Hyd are so efficient, their overall power draw per hash is lower even if their absolute wattage is higher. For example, the S21 XP Hyd draws 5676 W but delivers an impressive 473 TH/s, resulting in a remarkable efficiency of about 12 J/TH. By comparison, the Antminer S19j Pro consumes 3068 W at 104 TH/s, which works out to around 29.5 J/TH. In practical terms, this means a farm of S21 XP Hyds can achieve the same output as many more older S19j Pros while incurring a smaller power bill.
I always remind customers: electricity is your biggest ongoing cost. As Bitdeer warns, expensive power rates can completely erase mining profits, especially when using less efficient rigs like the S19j Pro.
Of course, used miners like the S19j Pro can still save energy per coin compared to doing no mining at all, but every bit of efficiency counts. In regions with very cheap electricity (such as parts of Canada or the Middle East with subsidized power), miners often tolerate older models and still turn a profit. But in places where power is expensive (such as much of Europe or Dubai), we consistently recommend the latest, most efficient models like the S21 XP Hyd to maximize profitability and stay competitive.
| Aspect | Antminer S21 XP Hyd (2025) | Antminer S19j Pro (2021) |
|---|---|---|
| Hashing Power (TH/s) | 473 TH/s | 104 TH/s |
| Power Draw (W) | 5676 W | 3068 W |
| Efficiency (J/TH) | 12 J/TH | 29.5 J/TH |
| Hash Rate vs Power Draw | Extremely efficient with high hash power despite higher wattage | Lower hash power with moderate power draw |
| Profitability Considerations | Lower Joules-per-hash makes it far more profitable, even in high-cost electricity markets | Needs cheap electricity to remain marginally profitable |
| Electricity Cost Impact | Much lower long-term power costs per bitcoin mined | Higher energy consumption per TH, increasing operational costs |
| Customer Recommendations | Best suited for competitive, high-cost electricity regions like Europe or Dubai | Viable in regions with very cheap electricity, such as parts of Canada or the Middle East |
| Practical Use Case | Ideal for large-scale mining operations prioritizing efficiency and profit | Sometimes used for small-scale setups where low upfront cost matters |
Reliability and Maintenance : New vs. Used Miners
New miners are generally highly reliable right out of the box. They haven’t been worn down by harsh environments or excessive usage, so the risk of failure is low. Moreover, any early-life defects (such as Dead on Arrival units) are covered by warranty. In contrast, used machines carry an unknown history—fans may be worn out, heatsinks dusty, and chips stressed from past use.
At MinerSource, we always recommend inspecting second-hand units carefully. High fan noise or overheating during initial testing often signals trouble. Every used miner should be fully tested before deployment. This includes running a stress test, checking hash rates and temperatures, and confirming that firmware is up to date.
Maintenance requirements are much higher for used hardware. Dust and debris quickly degrade performance, so frequent cleaning is essential. Clogged fans can cause overheating and even failure. We recommend a regular maintenance schedule: blowing out fans, wiping heat sinks, and even reapplying thermal paste every year or two. Without such care, a used miner’s lifespan can be significantly shortened. In our mining farms, newly purchased machines might only need basic upkeep, but older units often require fan replacements, power supply swaps, or even board repairs much sooner.
In short, used rigs tend to demand more maintenance and monitoring to stay reliable, while new units are generally low-maintenance and backed by warranties.
| Aspect | New ASIC Miners | Used ASIC Miners |
|---|---|---|
| Reliability | Highly reliable out of the box | Risk of hidden damage or wear |
| Warranty Coverage | Yes (covers DOA and early defects) | Usually no warranty |
| Testing Required | Minimal; standard startup checks | Comprehensive stress tests, firmware updates |
| Initial Condition | Clean, well-built, new components | Possible fan wear, dusty heatsinks, stressed chips |
| Maintenance Needs | Low – basic cleaning and monitoring | High – frequent cleaning, potential part replacements |
| Maintenance Tasks | Basic: occasional fan and heatsink checks | Advanced: frequent dusting, reapplying thermal paste, fan/power supply swaps |
| Lifespan Expectancy | Long, especially with warranty support | Shorter lifespan without consistent upkeep |
| Deployment Risk | Low – ready to mine | Higher – risk of underperformance or failure |
Warranty and Support: New vs. Used ASIC Miners
A major advantage of buying new ASIC miners is the manufacturer’s warranty. For instance, Bitmain provides a one-year warranty on all S21 models (and newer). If a new miner experiences a fault within this period, the manufacturer will either repair it or supply replacement parts at no additional cost. This safety net is a significant benefit for business buyers, reducing risk and potential downtime.
In contrast, used miners almost never come with a valid manufacturer’s warranty. Some vendors may offer a short-term or limited warranty, but most used units are sold “as is.” As D-Central points out, refurbished miners might come with a “limited warranty or none at all”. This means that any repairs – from replacing failing chips to fixing controller boards – will have to be covered by the buyer.
We always advise customers that buying used miners involves accepting weaker support. You should plan to spend time and money on repairs, as well as investing in test equipment like power meters and decibel readers to identify potential issues early.
| Aspect | New ASIC Miners (e.g., Bitmain S21) | Used ASIC Miners |
|---|---|---|
| Warranty Coverage | Yes (1 year from manufacturer) | Rarely – often “as is” or with very limited warranty |
| Support Quality | Full support: repairs or parts replacement at no cost | Weak support: buyer covers all repair costs |
| Repair Costs | Covered by manufacturer during warranty | Buyer must cover all repairs (chips, boards, etc.) |
| Business Risk | Low – warranty reduces downtime risk | High – potential for frequent failures and costs |
| Recommended for | Business buyers seeking reliability | Budget-conscious buyers willing to manage repairs |
| Additional Considerations | Manufacturer handles repairs, ensuring quality | Buyer must invest in test tools and time for diagnostics |
Cost, ROI, and Long-Term Value : New vs. Used ASIC Miners
For most buyers, money is the biggest factor. Used miners cost significantly less upfront than new ones—often priced 30–50% lower. In simple terms, you might be able to purchase two or even three used miners for the price of one new unit. This lower initial investment can effectively double your initial hashing power. Since mining margins are often thin, this advantage can help you reach break-even faster.
For example, if a new miner costs $3,000, while a used one of the same model is $1,500, the used unit’s ROI time is nearly half—about 150 days compared to 300 days in this scenario. Many real miners report selling off old hardware during market downturns, making these bargain machines a smart move when the market eventually recovers.
On the flip side, new miners take longer to pay off because of their higher initial price. However, once deployed, they tend to earn consistently and last longer. We always advise customers to calculate the total cost of ownership, considering not just the purchase price but also years of electricity and maintenance expenses. While new units may cost more upfront, their superior efficiency and warranty coverage generally lead to lower total costs over time. In practice, large data centers often prefer the latest models for precisely this reason – the higher initial investment is justified by lower per-hash costs and fewer unexpected repairs.
| Aspect | New ASIC Miners | Used ASIC Miners |
|---|---|---|
| Upfront Cost | High | 30–50% lower |
| Hash Power per Dollar | Lower | Higher – can double initial hash rate per dollar |
| Break-even Time | Longer (e.g., 300 days) | Shorter (e.g., 150 days) |
| Long-term Profitability | Higher due to efficiency and warranty | Lower, may require cheap electricity and more maintenance |
| Risk of Repairs | Lower – covered by warranty | Higher – buyer covers all repair costs |
| Suitability | Ideal for large data centers and long-term mining | Suitable for budget-conscious buyers seeking fast ROI |
| Market Considerations | More resilient in market downturns | Bargain machines can be profitable if market recovers |
Resale Value : New vs. Used ASIC Miners
Both new and used ASICs usually have some resale value, since there’s an active second-hand market for miners. Well-known models tend to hold value better. For example, a broker’s guide notes that some used miners like the Whatsminer M30S “are affordable and widely available” and maintain strong resale value. In general, you can often sell a used machine later if crypto prices rise or you want to upgrade. However, rapid tech turnover and difficulty hikes mean ASICs depreciate faster than say real estate. New machines lose warranty and value once operated, and older generation models can drop in price when newer series come out. So, while we count on getting some money back by reselling miners, we also expect used units to sell for much less than new.
Key Points:
- New ASICs: Latest chips give the highest hash rate and best energy efficiency. Full manufacturer warranty (often 1 year) covers defects. Lower maintenance initially. High upfront cost and longer payback.
- Used ASICs: Much cheaper to buy, letting you deploy more hashpower for less money. Faster break-even if earnings hold up. However, they are older tech (lower hashes for same power), usually lack warranty, and may have hidden wear (noisy fans, dust) requiring more upkeep.
| Feature | Brand New ASIC | Used/Refurbished ASIC |
|---|---|---|
| Initial Cost | High (latest model price) | Lower (often 30–50% discount) |
| Hashrate (Performance) | Very high (e.g. 200 TH/s for S21 Pro) | Lower (e.g. ~90TH/s for older S19) |
| Power Efficiency | Top tier (e.g. ~12J/TH on S21 XP Hyd) | Much lower (e.g. ~32.5/TH on S19) |
| Electricity Usage | More absolute watts but far more hashing (better W/TH) | Less absolute W, but much higher watts per TH |
| Manufacturer Warranty | Yes (commonly 365 days on Bitmain S21 models) | Generally no official warranty |
| Reliability | New parts, lower failure risk | Potential wear and failures (fans, boards) |
| Maintenance Needs | Lower initially (basic cleaning) | Higher (cleaning dust, repaste, replace fans) |
| Lifespan | Longer (fresh device) | Shorter (already used portion) |
| Resale Value | Can be resold but quickly loses value with new model releases | Active second-hand market (some models still sell well) |
| ROI Potential | Slower (bigger investment) | Faster (cheaper machine) |
Conclusion
In summary, brand-new ASIC miners deliver the best performance, efficiency, and reliability, at the cost of a higher price and longer payback period. They include full warranty coverage and tend to need less maintenance early on. Used ASICs are budget-friendly, letting you spin up capacity quickly, but you trade that for older hardware, no warranty, and potentially higher running costs (power and repairs).
Ultimately, the choice depends on your situation. If you have cheap electricity and limited capital, used miners can make sense as a stepping stone. If you are building a large-scale farm aiming for long-term competitiveness, investing in the newest ASICs usually pays off through higher uptime and efficiency. In my experience advising mining companies and B2B buyers, weighing these factors — performance needs, power cost, risk tolerance, and warranty — leads to the right decision for each project.
