How to Undervolt Your CPU: Lower Temps Without Losing Speed

Quick Answer

Undervolting your CPU reduces the voltage supplied to the processor below stock levels, which lowers heat output without reducing clock speeds. Done correctly, it gives you cooler temperatures, quieter fans, and the same performance, making it one of the most effective free optimisations available to SA PC builders and laptop users.

What Undervolting Actually Does to Your CPU

Every CPU leaves the factory with a voltage curve that is deliberately conservative. Manufacturers set voltages high enough to ensure stability across millions of units with varying silicon quality. Your specific chip may run perfectly stable at significantly lower voltages than the stock setting. Undervolting exploits this headroom by reducing the voltage-to-frequency ratio, which directly reduces heat output because power consumption scales with the square of voltage.

For desktop users running Ryzen or Intel processors in South African summer conditions, this matters. Ambient temperatures in Joburg or Durban can push case thermals noticeably higher than in European or North American climates for which most cooling guides are written. Getting your CPU 5 to 10 degrees Celsius cooler through undervolting reduces thermal throttling risk and extends component longevity.

Tools and Methods: How to Undervolt in 2026

The approach differs between Intel and AMD processors.

For Intel 12th gen and later (Alder Lake, Raptor Lake, Arrow Lake), use the Extreme Tuning Utility (Intel XTU) or your motherboard BIOS to adjust the core voltage offset. You apply a negative offset, for example minus 50mV to minus 100mV, and test for stability. Raptor Lake chips (13th and 14th gen) particularly benefit from undervolting because they run hot at stock settings.

For AMD Ryzen 5000 and 7000 series, Curve Optimizer in the BIOS or AMD's Ryzen Master software is the primary tool. Curve Optimizer lets you adjust the voltage-to-frequency curve per core, allowing more aggressive undervolting on your strongest cores (which boost highest) while being conservative on weaker cores. A starting point of minus 20 to minus 30 all-core is reasonable before testing.

For laptop users, undervolting is increasingly restricted by firmware. Intel laptops running 12th gen and newer may have voltage offset locked out. However, AMD-based laptops often still allow Curve Optimizer adjustments through Ryzen Master even without BIOS access.

Testing Stability After Undervolting

After applying your undervolt, stability testing is non-negotiable. A crash during gaming or work is worse than running at stock settings. Use a combination of a CPU stress test tool running for at least 30 minutes and then a real-world workload like a long gaming session or a video render. Temperature monitoring software running in the background will show you the thermal gains clearly.

If you encounter instability (crashes, BSOD, or freezes), reduce the offset magnitude in 5 to 10mV increments until stable. The sweet spot varies per chip and is worth finding through methodical testing.

Frequently Asked Questions

Is undervolting safe for my CPU?

Yes. Undervolting only reduces voltage below stock levels. The worst outcome from too aggressive an undervolt is system instability or crashes, which are resolved by dialling back the offset. It does not damage hardware.

How much temperature reduction can I expect?

Results vary widely by chip and cooling setup, but typical gains range from 5 to 15 degrees Celsius under sustained load. Laptop users tend to see larger gains because compact thermal designs run closer to their thermal limits at stock voltages.

Can undervolting improve gaming performance?

It can, indirectly. If your CPU was thermally throttling at stock voltages, undervolting allows it to sustain higher boost clocks for longer, which improves frame rates in CPU-bound gaming scenarios.