What Is Overclocking and Undervolting an ASIC Miner?
Overclocking and undervolting are the two main ways miners tune an ASIC beyond its factory-set stock configuration, trading hashrate and efficiency against each other depending on the goal. Both are normally achieved through firmware settings that control the chip frequency and voltage, and both are at the core of why custom ASIC firmware exists in the first place.
What Is Overclocking?
Overclocking means increasing the operating frequency of the ASIC chips beyond their factory default, which increases hashrate — and therefore potential earnings — at the cost of higher power consumption and increased heat output. For example, a Antminer L7 rated at 8.8-9.5 GH/s stock is sometimes pushed by experienced operators with strong cooling to 10.0-10.5 GH/s or more through overclocking.
Overclocking only makes sense when your cooling and power infrastructure can safely absorb the extra heat and current draw — pushing an air-cooled unit too hard without adequate airflow risks thermal throttling, instability, or in extreme/prolonged cases, shortened hardware lifespan.
What Is Undervolting?
Undervolting works in the opposite direction: reducing the voltage (and often frequency slightly) to lower power consumption, at the cost of a small reduction in hashrate. Because the relationship between voltage and power is not linear, a modest voltage reduction can often cut power draw by a much larger percentage than the hashrate loss — meaningfully improving the machine's efficiency (J/TH) figure.
This makes undervolting especially popular among miners paying higher electricity rates, where the better efficiency translates directly into a healthier profit margin, as well as anyone who wants a quieter, cooler-running machine for a home or office environment.
Overclocking vs Undervolting: Which Should You Use?
| Goal | Recommended Approach |
|---|---|
| Maximize raw hashrate/earnings, cheap electricity | Overclocking (with strong cooling) |
| Minimize electricity bill, expensive power | Undervolting |
| Quiet home/office operation | Undervolting |
| Maximum long-term hardware lifespan | Undervolting or stock settings |
Why Stock Firmware Often Leaves Performance on the Table
Manufacturers configure factory/stock firmware conservatively, aiming for safe, reliable operation across a huge range of real-world cooling and ambient conditions worldwide — not the absolute best efficiency or hashrate for any single user's specific setup. This is exactly the gap that custom ASIC firmware is built to close, typically offering a 10-20% performance increase or 10-30% power reduction depending on the model, by exposing finer-grained frequency, voltage, and fan-curve controls than stock firmware provides.
Safety Considerations
Always monitor chip temperatures after any tuning change — sustained high temperatures are the main driver of long-term hardware degradation.
Make incremental changes and test stability over several hours before pushing further.
Third-party firmware may affect manufacturer warranty coverage — weigh this against the efficiency/performance gains for your situation.
Keep the original stock firmware backed up so you can always revert if needed.
You can get properly tuned custom firmware, developed specifically for your ASIC model, through our Custom ASIC Firmware page.
