Begin by lowering your GPU core voltage. A reduction of 50-150mV from stock often yields the most significant gains in electrical efficiency without sacrificing hashrate. This single adjustment directly impacts your bottom line by decreasing power consumption, a critical factor for mining profitability when electricity costs are high. Stability under this new voltage is your primary benchmark; the card must run your target cryptocurrency algorithm for 24 hours without errors.
Focus your performance tuning on the memory subsystem, not the graphics core. For Ethereum Classic or Ravencoin, the hash algorithm is heavily dependent on memory bandwidth. Increasing your memory clock by 800-1200MHz on GDDR6 or 200-400MHz on HBM can produce a 5-15% boost in hashrate. Monitor for memory temperature; sustained operation above 90°C will degrade performance and hardware lifespan. Enhanced cooling, through replaced thermal pads or an aggressive fan curve, is non-negotiable for maintaining these elevated memory rates.
The final stage involves a delicate balance between the core clock and power limit. A slight core underclock of -100 to -200MHz can further reduce power draw, allowing more thermal and electrical headroom for the memory overclock. Set a conservative power limit, around 70-80%, to cap total board consumption. Your optimal settings are those that deliver the highest stable hash output per watt, not merely the highest absolute hashrate. This data-driven approach to optimizing each parameter–voltage, memory, and power–transforms a standard graphics card into a dedicated, profit-focused mining instrument.
Algorithm-Specific Tuning: The Final Frontier for Hashrate
Forget a universal overclock; your settings must be tailored to the mining algorithm. An Ethereum Classic configuration on the KAWPOW algorithm will destroy your card’s efficiency. For memory-intensive algorithms like Ethash, push the memory clock aggressively. My RTX 3080 runs a +1200 MHz memory offset, paired with a core clock *undervolt* of 1150mV at 1500 MHz. This pairing reduces power draw by 90W while adding 12 MH/s to the hash rate, a direct result of optimizing the memory bandwidth bottleneck.
Voltage-Frequency Curving for Maximum Efficiency
Static voltage adjustments are outdated. Modern tuning uses the voltage-frequency curve to lock the graphics card at its most efficient point. I lock my GPUs to a specific voltage and frequency, preventing them from drawing excess power during less demanding cycles. For a GTX 1660 Super mining Ergo, the optimal point is 725mV at 1300 MHz core. This setting yields 68 MH/s at just 75W, a 30% improvement in performance per watt over stock settings. This precise control is non-negotiable for long-term profitability.
Stability testing requires more than a few hours. Run your new settings for a full 24-48 hours while monitoring for rejected shares. A rejection rate over 1% indicates unstable memory, while hardware errors point to an insufficient core voltage. Enhanced cooling is mandatory; maintaining memory junction temperatures below 90°C on GDDR6X cards is critical to prevent thermal throttling and preserve the card’s lifespan. The output you see on day one will degrade if cooling is inadequate.
Core Clock and Memory Offset
For Ethereum mining on an RTX 3080, begin with a core clock underclock of -200 MHz and a memory overclock of +1200 MHz. This setting prioritises memory bandwidth, which directly dictates hashrate for the Ethash algorithm, while reducing core voltage for better power efficiency. The graphics card’s memory, especially GDDR6X, often has more tuning headroom than the core; pushing it increases your hash output without a proportional rise in power draw. Monitor your hashrate stability in your mining software; a 2-3 MH/s fluctuation indicates unstable memory settings.
Contrast this with mining Ravencoin, which uses the KawPow algorithm. Here, the core clock’s performance is far more critical. Apply a slight core clock boost of +150 MHz and a more conservative memory offset of +600 MHz. KawPow stresses the GPU’s compute units, so a higher core clock increases the hash rate effectively. This demonstrates that algorithm dictates strategy: memory-focused tuning for Ethash, balanced core and memory for KawPow. Always validate settings over a 24-hour period to confirm stability and peak performance.
Voltage control is the linchpin of this entire process. A lower GPU voltage, often achievable by locking the card at a specific point like 725mV, drastically cuts power consumption. This tuning enhances your mining efficiency, measured in megahash per second per watt (MH/s/W). A card drawing 220W instead of 280W for the same hashrate significantly improves long-term profitability and reduces thermal output, which in turn allows your cooling system to maintain lower temperatures and guarantee long-term stability. The goal is a cooler, quieter, and more cost-effective mining operation.
Final optimisation requires iterative testing. Increment memory clock by +50 MHz steps, running a benchmark for 15 minutes at each stage until you encounter invalid shares or a driver crash. Then, dial back by -25 MHz. This method finds the absolute limit of your specific card’s memory. Pair this with fan curves that keep GPU memory junction temperatures below 96°C for GDDR6X and below 90°C for other types. This data-driven approach to tuning finds the perfect equilibrium between maximum hashrate, system stability, and hardware longevity.
Voltage and Power Limit: The Core of Mining Efficiency
Undervolt your card. This is the single most critical step for optimizing mining performance, as it directly links reduced electrical draw to enhanced profitability. Lowering the GPU core voltage decreases power consumption and heat output dramatically, which allows your cooling system to maintain a lower operating temperature. A cooler card can sustain higher memory clocks, directly boosting your hashrate without compromising stability. For an NVIDIA RTX 3080, I aim for a voltage curve around 725mV locked at a core clock of 1150 MHz; this often reduces power draw from 340W to under 230W while maintaining the same cryptocurrency output.
Set a strict power limit, typically between 60% and 70% of the card’s maximum. This acts as a hard cap, preventing power spikes and enforcing the efficiency gains from your voltage tuning. The specific algorithm dictates the optimal setting: Ethereum’s Ethash is memory-intensive, so you can aggressively lower the power limit, while Conflux’s Octopus demands more from the graphics core, requiring a slightly higher cap. My data shows that an RTX 3070 tuned to 60% power limit (around 130W) frequently achieves 98% of its maximum hashrate while using 40% less electricity, a clear win for long-term mining profitability.
The interplay between voltage, power limit, and memory frequency is where fine-tuning separates good results from great ones. After locking a low voltage, increase your memory offset in small increments, stress-testing for several hours to confirm stability. The goal is to find the highest stable memory clock your card can run within its new, lower power envelope. This precise balancing act maximizes the hashrate per watt, the true measure of a mining rig’s performance. An unstable configuration will produce invalid shares, negating any perceived gains from a higher hashrate.
Cooling and Stability Check
Maintain GPU core temperatures below 70°C and memory junction temperatures under 95°C for sustained operation. High memory temperatures are a primary cause of throttling, silently eroding your hashrate. Use tools like HWiNFO64 to monitor ‘GPU Memory Junction Temperature’, a critical metric often hidden from standard monitoring software. For GDDR6X cards, which run notoriously hot, replacing thermal pads can drop memory temperatures by 15-20°C, directly translating to higher stable memory clock settings.
Stability in mining is not about a lack of crashes, but consistent data output. Your true measure is the number of invalid or rejected shares reported by your mining pool over a 24-hour period. Aim for a reject rate below 1%. A higher rate indicates unstable memory overclocks, even if the system appears to run fine. The tuning process is iterative:
- Apply your target memory and core clock offsets.
- Run the miner for a minimum of six hours, monitoring the share acceptance rate.
- If rejected shares exceed 1%, reduce the memory clock offset in 25 MHz increments.
This data-driven approach finds the card’s true optimal point, not just its highest possible clock speed.
Aggressive fan curves are counter-productive for long-term profitability. A fan running at 100% will fail much sooner than one at 70%. Instead, focus on ambient airflow. A simple, positive-pressure setup with multiple intake fans moving cool air directly across the graphics cards is more effective and quieter than maxing out individual GPU fans. This environmental cooling enhances the efficiency of each card’s own cooling solution, allowing for lower fan speeds and reduced wear while maintaining ideal operating temperatures.
Different mining algorithms exert unique thermal loads. Ethereum’s Ethash was memory-intensive, while others like Kaspa’s kHeavyHash are more core-dependent. Your cooling efficiency and stability checks must be re-calibrated for each algorithm you mine. A stable setting for one cryptocurrency may cause immediate instability in another. Always conduct a full stability check after switching to a new algorithm, as the thermal and power load profile will have shifted, requiring fresh tuning for maximum output and card health.
