The Definitive Guide to Buying Used GPUs: What 19 Mining Cards Taught ltt

This article is based on comprehensive testing conducted by Linus Tech Tips
Source: Linus Tech Tips – “I bought 19 used GPUs – was it worth it?”

Introduction: The Great GPU Dilemma

The graphics card market has experienced unprecedented volatility over the past few years. Cryptocurrency mining created a perfect storm of high demand, inflated prices, and chronic shortages that left gamers scrambling for alternatives. New GPUs became luxury items, with prices reaching astronomical heights and availability remaining frustratingly low.

As the crypto mining boom eventually cooled, a new phenomenon emerged: thousands of previously-mined graphics cards flooding the secondhand market. Suddenly, eBay, Facebook Marketplace, and other platforms were awash with GPUs that had spent months or even years crunching cryptocurrency algorithms 24/7. For budget-conscious PC builders and gamers, these cards represented an attractive opportunity – but were they too good to be true?

The tech media and online communities were divided. Some warned that mining cards were ticking time bombs, degraded by constant use and destined to fail. Others argued that fears were overblown, pointing out that mining workloads might actually be less damaging than gaming. The debate raged on, but concrete evidence remained elusive.

That’s where the team at Linus Tech Tips stepped in with an ambitious project: purchase 19 used GPUs from the wild west of online marketplaces and subject them to over 1,500 rigorous tests to settle the argument once and for all.

The Testing Framework: A Scientific Approach

The Shopping Spree

The LTT team took a deliberately random approach to their purchases, mimicking what a typical consumer might experience. They sourced 19 GPUs anonymously from 17 different eBay sellers, avoiding any cherry-picking or seller vetting that might skew results. The only requirement was that the cards had to have been desirable for mining and hard to find for gamers during the shortage.

Their haul included:

AMD Radeon RX 5700 series cards: Known for exceptional power efficiency and lower demand compared to NVIDIA alternatives, making them incredibly profitable for miners
NVIDIA RTX 3060s: Popular due to their high VRAM-to-price ratio, despite NVIDIA’s failed attempts to limit their hash rates through driver restrictions
NVIDIA RTX 3070s and 3080s: Simply powerful cards that commanded premium prices and delivered excellent mining performance

The Testing Gauntlet

The LTT team designed a comprehensive testing protocol that would reveal any performance degradation, thermal issues, or component failures:

Quick Diagnostic Testing

MSI Combustor: A rapid stress test that reveals clock speed capabilities and thermal performance
Visual inspection: Checking for physical damage, wear patterns, loose components, and unusual odors
Basic functionality: Ensuring cards POST and display output correctly

Comprehensive Performance Analysis

Gaming benchmarks: Six different games tested at three resolutions (1080p, 1440p, 4K)
Thermal monitoring: Temperature measurements under sustained loads
Clock speed analysis: Monitoring boost clocks and thermal throttling behavior
VRAM integrity testing: Using IDA 64’s GPU benchmark to detect memory errors

Control Group Methodology

Since new versions of these older cards were no longer available, the team used lightly-used GPUs from their own stock as control samples. While not perfect, this provided a reasonable baseline for comparison and helped identify cards performing significantly outside normal parameters.

The Results: Separating Fact from Fiction

Performance Findings: Mostly Good News

The headline finding was remarkably positive: the vast majority of used GPUs performed exactly as expected, with no discernible performance degradation from their mining service.

RTX 3080 Results

All mining cards performed within normal parameters, with clock speeds and gaming performance matching expectations. Interestingly, one of their control cards actually exhibited worse performance, with inconsistent frame times that would manifest as stuttering during demanding game sequences. This served as a reminder that even lightly-used hardware can develop issues over time.

The EVGA RTX 3080 actually performed slightly better than expected, earning praise from the LTT team. This was particularly poignant given EVGA’s subsequent exit from the GPU market.

RTX 3070 Results

Every single RTX 3070 performed flawlessly, with minimal variance between cards. Clock speeds remained consistent, thermal performance was excellent, and gaming benchmarks showed no concerning deviations from expected performance levels.

RTX 3060 Analysis

Most RTX 3060s performed admirably, but this category revealed the testing methodology’s first major red flag. One card, the Gigabyte Eagle OC, showed significantly lower average clock speeds in MSI Combustor – an immediate warning sign that something was amiss.

The Ventus 2X model performed slightly below expectations but within acceptable parameters. When lightly overclocked, it easily returned to expected performance levels, suggesting the lower clocks were likely due to conservative factory settings rather than degradation.

RX 5700 XT Evaluation

The AMD cards presented an interesting puzzle. One Sapphire Pulse card showed concerning clock speed behavior in synthetic tests, but thermal performance remained excellent. This ruled out obvious thermal throttling or mining BIOS modifications as causes.

However, when tested in real-world gaming scenarios, the card performed perfectly. This highlighted an important limitation of quick diagnostic tests – they don’t always reflect real-world performance.

The Problem Children: When Things Go Wrong

Not everything in the used GPU market is sunshine and savings. The LTT testing revealed several concerning issues that buyers need to watch for:

The Thermal Disaster

The Gigabyte Eagle OC RTX 3060 that showed poor clock speeds in initial testing proved to have severe thermal issues. Under load, temperatures far exceeded safe operating ranges, causing aggressive thermal throttling that crippled performance. This card was clearly suffering from cooling system failure – possibly due to dried thermal paste, fan problems, or heat sink mounting issues.

VRAM Failures

The same Eagle OC card also failed VRAM integrity testing, throwing errors that indicated memory module problems. This type of failure is particularly concerning because it can cause system crashes, artifacts, and data corruption.

Physical Condition Issues

Several cards arrived in questionable physical condition:

Strange odors (described as “vinegar-like”)
Rattling components (loose fans or heat sink elements)
Excessive dust accumulation
General wear and tear beyond normal expectations

One MSI RX 5700 XT exhibited a notable rattle, though it otherwise appeared functional. These physical issues don’t necessarily indicate performance problems but suggest previous owners may not have maintained the cards properly.

Financial Analysis: The Bottom Line

Even accounting for complete failures, the economics of buying used remained compelling. The LTT team’s purchases delivered approximately 22% savings compared to new pricing at the time of purchase. This calculation included their “asking price only” approach – they didn’t haggle, wait for auctions, or hunt for deals.

Even more impressively, when removing the cost of their one definitively broken GPU from calculations, savings still reached 18.5%. This suggests that even with a reasonable failure rate, used GPU purchases offer substantial financial benefits.

The team noted that more patient buyers could achieve even better savings through:

Auction bidding rather than “Buy It Now” purchases
Negotiating with sellers
Waiting for better deals to appear
Purchasing during market downturns

Debunking the Myths: Science vs. Speculation

The LTT testing provided concrete evidence to address several persistent myths about used GPUs:

Myth #1: Mining Degrades GPU Performance Over Time

The Reality: This proved to be largely false. GPUs don’t “wear out” from computational work the way mechanical components might. The silicon itself doesn’t degrade from processing workloads, whether mining or gaming.

In fact, mining workloads can be less stressful than gaming in several ways:

Consistent temperatures: Mining typically runs cards at steady, moderate temperatures rather than the heating/cooling cycles common in gaming
Stable clock speeds: Mining software often undervolts cards and runs them at consistent speeds for efficiency
Lower peak loads: Gaming can create sudden spikes in power draw and temperature that are more stressful than steady mining loads

Myth #2: All Mining Cards Are Abused and Neglected

The Truth: The LTT findings suggest the opposite may be true. Most miners have financial incentives to maintain their hardware properly since card failures directly impact profitability. Many mining operations run cards in well-ventilated environments with careful temperature monitoring.

The majority of cards in the LTT test arrived in good physical condition, requiring only basic cleaning. This aligns with the theory that serious miners treat their GPUs as business assets rather than disposable components.

Myth #3: Avoiding Used Cards “Punishes” Miners

The Economic Reality: Refusing to buy used cards doesn’t harm previous miners – it only limits consumer options and potentially increases electronic waste. Miners who want to sell will find buyers eventually, or the cards will end up in landfills.

From an economic perspective, every functional GPU not in use essentially requires a new one to be manufactured to meet demand. This increases overall production, resource consumption, and environmental impact.

Myth #4: New Cards Are Always More Reliable

The Statistical Truth: Electronics follow predictable failure patterns known as the “bathtub curve.” Defective units typically fail early (within warranty periods), while properly functioning units tend to operate reliably for years regardless of workload history.

The LTT team even experienced this phenomenon firsthand when one of their control cards exhibited worse performance than the used mining cards. Age and usage history don’t guarantee reliability in either direction.

The Comprehensive Buyer’s Guide: Shopping Smart

Phase 1: Pre-Purchase Research

Communicate with Sellers

Most sellers are surprisingly honest about their cards’ history when asked directly. Key questions to ask:

Was the card used for mining? For how long?
What were typical operating temperatures?
Have there been any performance issues or repairs?
Why are they selling?
Can they provide recent screenshots of the card running?

Research the Specific Model

Not all GPUs are created equal, even within the same chipset family. Research:

Factory overclocks and power limits
Common failure modes for that specific model
Availability and cost of replacement fans or thermal solutions
BIOS modification history (some mining cards may have modified firmware)

Understand Market Pricing

Use tools like eBay’s “sold listings” feature to understand realistic pricing for specific models. Factor in:

Condition and seller reputation
Included accessories (original box, cables, documentation)
Remaining warranty coverage
Comparable new product pricing

Phase 2: The Inspection Process

Physical Examination

Upon receiving a card (or during in-person pickup):

Visual Inspection Checklist:

Overall cleanliness and dust accumulation
Fan condition and smooth rotation
Heat sink mounting and thermal interface material visibility
Capacitor condition (no bulging or leakage)
PCB condition (no burn marks, damaged traces, or component damage)
Connector condition (clean pins, no corrosion)

The “Shake Test”:
Gently shake the card and listen for rattling sounds that might indicate:

Loose fan bearings
Detached heat sink components
Loose capacitors or other components
Foreign objects inside the shroud

Odor Assessment:
Unusual smells can indicate:

Overheating damage (burnt electronics smell)
Capacitor problems (fishy or chemical odors)
Environmental damage (mold, moisture, smoke exposure)

Initial Power-On Testing

Before installing in your primary system:

Test in a spare system if possible
Verify the card is detected properly in BIOS/UEFI
Check for display output at native resolution
Listen for unusual fan noises or behaviors

Phase 3: Performance Validation

Quick Diagnostic Tests

MSI Combustor (or similar stress testing software):

Run for 15-30 minutes to assess thermal performance
Monitor clock speeds for throttling behavior
Check for artifacts, crashes, or system instability
Compare results to online benchmarks for your specific model

Temperature Monitoring:

GPU temperatures should remain below 85°C under full load for most cards
Memory junction temperatures (if available) shouldn’t exceed 95°C
Fan curves should respond appropriately to temperature changes

Comprehensive Testing

Gaming Benchmarks:
Test with demanding games at various settings to ensure stable performance across different workloads. Look for:

Consistent frame rates without sudden drops
No visual artifacts or rendering errors
Stable temperatures during extended gaming sessions

Memory Testing:
Use tools like HWiNFO64 or GPU-Z to monitor for:

Memory errors or corrections
Unusual memory clock behavior
Temperature sensor readings (if available)

Stress Testing:
Run extended stress tests (30-60 minutes) using:

FurMark for thermal stress
Unigine Heaven/Valley for gaming-like loads
Mining software (if comfortable) to replicate previous workloads

Phase 4: Problem Resolution

Fixable Issues

Some problems can be resolved with basic maintenance:

Thermal Issues:

Thermal paste replacement (usually $5-15 in materials)
Fan cleaning or replacement
Dust removal from heat sinks
Improving case airflow

Software Issues:

BIOS flashing to restore stock settings
Driver clean installation
Overclocking profile reset

Minor Physical Issues:

Fan replacement (often $20-50)
Thermal pad replacement
Basic cleaning and maintenance

Deal-Breakers

Some issues indicate cards that should be returned or avoided:

VRAM errors or failures
Persistent artifacts or display corruption
Excessive temperatures that can’t be resolved with cleaning
Physical damage to PCB or critical components
Cards that fail to POST or aren’t detected by systems

Phase 5: Post-Purchase Optimization

Performance Tuning

Even healthy used cards can benefit from optimization:

Custom fan curves for better thermal performance
Undervolting to reduce power consumption and heat
Memory clock optimization
Power limit adjustments based on your specific use case

Maintenance Schedule

Establish regular maintenance to extend card life:

Quarterly dust cleaning
Annual thermal paste replacement
Fan lubrication or replacement as needed
Temperature monitoring during intensive use periods

The Environmental and Economic Case

Environmental Impact

The environmental argument for buying used GPUs is compelling:

Resource Conservation:

Extends the useful life of existing silicon
Reduces demand for new semiconductor production
Minimizes mining of rare earth elements
Decreases manufacturing energy consumption

E-Waste Reduction:

Prevents functional hardware from entering waste streams
Reduces landfill burden from electronic components
Supports circular economy principles
Maximizes value extraction from manufactured goods

Carbon Footprint:
GPU manufacturing is energy-intensive, involving:

Silicon wafer production and processing
Complex chip fabrication processes
Assembly and packaging operations
Global shipping and distribution
Retail infrastructure and marketing

Buying used eliminates most of these environmental costs while delivering identical functionality.

Economic Considerations

Consumer Benefits

Immediate savings: 15-25% typical price reduction
Faster upgrades: Lower costs enable more frequent hardware updates
Budget flexibility: Savings can be allocated to other system components
Risk mitigation: Lower initial investment reduces financial exposure

Market Effects

Price pressure: Used market availability helps moderate new card pricing
Increased accessibility: Makes PC gaming more affordable for budget-conscious consumers
Market efficiency: Improves allocation of existing hardware resources

Long-term Value

Well-maintained GPUs often retain significant resale value, making them excellent investments for users who upgrade regularly. The secondary market provides:

Easy upgrade paths when better cards become available
Reduced total cost of ownership through resale value retention
Flexibility to experiment with different hardware configurations

Risk Assessment and Mitigation Strategies

Understanding the Risks

Technical Risks

Component failure: Any electronic device can fail unexpectedly
Performance degradation: Rare but possible with extreme abuse
Compatibility issues: Driver problems or system integration challenges
Hidden damage: Issues not apparent during initial testing

Financial Risks

Total loss: Card failure outside return windows
Repair costs: Some issues may require professional service
Opportunity cost: Time spent testing and troubleshooting

Practical Risks

Warranty void: Most used cards have no manufacturer warranty
Support limitations: Reduced access to official technical support
Documentation gaps: Missing manuals, software, or accessories

Mitigation Strategies

Purchase Protection

Platform choice: Use marketplaces with strong buyer protection (eBay, PayPal)
Payment methods: Credit cards offer additional dispute resolution options
Documentation: Keep detailed records of communications and testing results
Timeline awareness: Understand return windows and dispute deadlines

Technical Preparation

Testing capability: Ensure you can properly evaluate cards before return periods expire
Backup plans: Have alternative hardware available during testing phases
Knowledge building: Understand basic GPU troubleshooting and maintenance
Tool acquisition: Invest in basic testing software and monitoring tools

Financial Planning

Budget buffer: Account for potential failures in upgrade budgets
Insurance consideration: Some homeowner’s/renter’s policies cover electronics
Failure planning: Understand repair costs and replacement timelines
Incremental approach: Consider buying one card first to gain experience

Advanced Topics and Considerations

Mining-Specific Modifications

BIOS Modifications

Some mining cards may have modified firmware that:

Reduces power limits for efficiency
Alters memory timings for better hash rates
Changes voltage curves for stability
Disables certain features or protections

Detection Methods:

GPU-Z can identify modified BIOSes
Clock speed behavior may indicate modifications
Power consumption patterns might differ from stock
Mining software may report different capabilities

Resolution Options:

TechPowerUp maintains extensive BIOS databases
Many cards can be flashed back to stock firmware
Some modifications may actually improve efficiency
Professional services can handle complex cases

Hardware Modifications

Less common but possible physical modifications:

Thermal pad upgrades for better cooling
Fan replacements for quieter operation
Power delivery modifications for higher efficiency
Custom cooling solutions

Specific Card Categories

High-End Cards (RTX 3080/3090, RX 6800 XT/6900 XT)

Higher absolute savings potential
More complex cooling systems require careful inspection
Power delivery components under greater stress
Higher repair costs if issues arise

Mid-Range Cards (RTX 3060/3070, RX 6600/6700 XT)

Best balance of savings and risk
Simpler designs with fewer failure points
Easier to replace if problems develop
Good performance per dollar ratios

Budget Cards (GTX 1660 series, RX 5500 XT)

Lower absolute savings but still worthwhile percentages
Generally reliable with fewer premium features to fail
Easy to test and evaluate
Excellent for budget builds and secondary systems

Market Timing and Trends

Seasonal Patterns

Post-holiday: Higher supply as people upgrade gifts
Summer months: Increased mining activity historically drove prices up
New generation launches: Older cards flood the market
Cryptocurrency cycles: Mining profitability affects supply

Economic Indicators

GPU MSRP changes: Official pricing affects used market values
Cryptocurrency prices: Mining profitability influences supply
General economic conditions: Consumer spending affects demand
Supply chain issues: New card availability impacts used pricing

Future-Proofing Your Purchase

Technology Transitions

Consider how long you’ll need the card to remain relevant:

Gaming Requirements Evolution

Resolution trends: 4K adoption rates and timeline
Ray tracing adoption: Current and future game requirements
VR development: Virtual reality hardware demands
Console generations: How console hardware affects PC requirements

Software Support Lifecycles

Driver support: How long manufacturers maintain driver updates
API compatibility: DirectX, Vulkan, and other standard evolution
Feature support: Hardware-specific features and their longevity
Security updates: Continued support for security vulnerabilities

Upgrade Planning

Position your used GPU purchase within a broader upgrade strategy:

Incremental Improvements

Plan 2-3 year replacement cycles for maximum value
Consider used cards as stepping stones to newer technology
Balance performance improvements with cost considerations
Maintain upgrade flexibility through smart purchasing

System Balance

Ensure your used GPU purchase fits within overall system capabilities:

CPU bottlenecking: Avoid mismatched component performance
Power supply adequacy: Ensure PSU can handle card requirements
Cooling capacity: Verify case airflow can manage thermal loads
Memory requirements: Consider VRAM needs for intended use cases

Conclusion: Making the Smart Choice

The comprehensive testing conducted by Linus Tech Tips provides compelling evidence that the used GPU market offers excellent value for informed buyers. Their 19-card experiment demonstrated that the vast majority of previously-mined graphics cards perform identically to new hardware while offering substantial cost savings.

Key Takeaways

Performance fears are largely unfounded: Most used GPUs perform exactly as expected with no degradation from mining use
Due diligence is essential: Proper inspection and testing can identify the small percentage of problematic cards
Financial benefits are significant: Even accounting for failures, savings of 15-25% are achievable
Environmental impact is positive: Extending hardware life reduces waste and manufacturing demand
Risk can be managed: Proper marketplace selection, testing procedures, and buyer protection minimize exposure

Decision Framework

Consider used GPUs if you:

Want to maximize price/performance ratio
Are comfortable with basic hardware troubleshooting
Have access to proper testing tools and procedures
Can work within marketplace return windows for evaluation
Support environmental sustainability in electronics

Stick with new GPUs if you:

Require transferable warranty coverage
Have zero tolerance for potential failures
Need guaranteed availability of support and documentation
Are purchasing for mission-critical applications
Have unlimited budgets and prioritize convenience

The Bigger Picture

The used GPU market represents more than just a way to save money – it’s a practical implementation of circular economy principles that benefits consumers, reduces environmental impact, and challenges the notion that newer is always better. As the tech industry grapples with sustainability concerns and consumers face economic pressures, the secondary market for graphics cards offers a compelling alternative to the endless cycle of new product purchases.

The evidence is clear: with proper knowledge, testing procedures, and risk management, buying used GPUs can deliver exceptional value while giving perfectly functional hardware a second life. The question isn’t whether you can trust the used GPU market – it’s whether you can afford not to explore it.

The choice ultimately comes down to your personal risk tolerance, technical comfort level, and financial priorities. But armed with the insights from this comprehensive analysis, you can make that choice with confidence, knowing that the used GPU market offers legitimate opportunities for smart buyers willing to do their homework.

Whether you choose new or used, the most important factor is making an informed decision based on facts rather than fears. The Linus Tech Tips testing has provided those facts – now the choice is yours.