Undervolting
Lowering the voltage on a CPU/GPU below the stock value to reduce heat + power without losing performance. Works because chips are tested conservatively — most tolerate 50-100 mV less than default.
Tools: Intel XTU, AMD Ryzen Master, ThrottleStop, MSI Afterburner. Process: lower in 25 mV steps, run Prime95/Cinebench for 30 min, if crash → raise 10 mV. Gain: laptop gets 30 min extra battery + quieter fans; desktop can avoid thermal throttling. Concrete example: Ryzen 5800X can often be run at -100 mV on all cores. GPU undervolt: Nvidia/AMD set to 0.9V at stock clock = 30% less heat for 0% performance loss. Validate long-term stability — instability can be silent corruption (worse than crash).