Undervolting your CPU or GPU allows you to squeeze more performance out of it, lower its temperatures, and reduce your system's overall power consumption. Unlike overclocking, undervolting is relatively safe, as you don't risk damaging your expensive components by lowering the voltage in the long run. Still, if you don't do it correctly, you will encounter system instability, crashes, and even performance loss, which is the last thing you'd want while gaming or running productivity apps.

Even experienced PC builders like myself occasionally overlook essential details, which leads to disappointing results after an undervolt. The first time I undervolted my old Alienware 17 R3 gaming laptop's CPU, things didn't go as planned. Although I was immediately happy with the lower operating temperatures, I encountered BSODs (Blue Screen of Death) while playing games. So, if you want to avoid such stability issues, don't make the following mistakes while undervolting your CPU or GPU.

4 Lowering voltage dramatically

Extreme voltage reductions will cause more problems

Although lowering your voltage too much doesn't damage your CPU, it still causes other problems. When PC users first get into undervolting, they're often excited by the idea of lowering CPU and GPU temperatures by simply turning down the voltage slider. Unfortunately, undervolting is not that easy. Just like how you'd be careful while overclocking your CPU, you should be cautious while undervolting too. You can't just copy someone else's voltage settings from the internet because they have the same CPU and GPU; silicon quality varies from batch to batch.

Aggressive voltage reductions might seem to work at first, but you'll quickly encounter BSOD (Blue Screen of Death) errors, random restarts, and boot failures. I highly recommend reducing your CPU or GPU's voltage in steps of 20mV (or 0.02V) and taking your time to adequately stress test your PC to make sure you don't face any issues before lowering it any further. Smaller, systematic steps will help you find the ideal sweet spot voltage setting for your CPU or GPU quickly without unnecessary frustration.

3 Not testing your PC's stability

Running quick benchmarks isn't enough

This is a mistake that not only beginners but also seasoned PC enthusiasts make while undervolting their components. You can't guarantee that your undervolt is successful by running a benchmark tool like Cinebench for five minutes. Your PC may successfully pass the benchmark run but throw a random BSOD error two hours into your gaming session. Sometimes, your PC may take a few days to show signs of instability due to your voltage settings because you haven't opened the application that really pushes your CPU or GPU to its limits.

That's why extensive stability testing with dedicated tools is mandatory while undervolting to avoid problems down the line. This involves running programs like Prime95, OCCT, AIDA64, and FurMark for several hours to expose any instability due to your applied voltage settings. In some rare cases, even that might not be enough. So you'll also have to spend several hours playing demanding AAA titles to determine whether your CPU or GPU can manage reduced voltages across various workloads under long-term usage scenarios.

2 Ignoring other vital metrics

Voltage and temperature aren't the only metrics that matter

Most people get into undervolting to lower their CPU and GPU temperatures, which is why many overlook vital metrics like clock speeds and system responsiveness. Note that the goal of undervolting is not to reduce power consumption and heat without sacrificing the performance of your CPU or GPU as much as possible. If you reduce the voltage too much, your CPU or GPU will lower its clock speed to maintain stability. Sure, you may save power in the process, but that comes at the cost of performance. A successful undervolt is all about finding balance.

That's why it's important to monitor your hardware using a tool like MSI Afterburner after tweaking the voltage sliders. Pay close attention to the clock speeds; ideally, your CPU or GPU should run at the same speed it did before you undervolted it because lower temperatures should only allow it to boost higher for longer. Likewise, note how responsive your PC is. For instance, if your PC isn't as responsive when opening apps, i.e., during sudden load changes, it might indicate instability, and you'll have to increase the voltage.

1 Forgetting to document your changes

Record your voltage settings to avoid wasting time in the future

When you perform undervolting correctly with proper stability testing, finding the voltage sweet spot for your CPU and GPU will sometimes take days. It's as time-consuming as overclocking your components at the end of the day. So, not recording your voltage settings after a successful undervolt is an oversight that may lead to wasted effort in the long run. If you ever reinstall Windows on your PC or reset the BIOS settings to default values months or years later, you may struggle to recall the voltage settings you previously applied.

Troubleshooting and reverting to a stable baseline becomes a guessing game without proper documentation, and you'll find yourself undervolting your components from scratch, which wastes your time. So don't let all your hard work go to waste. Note down your voltage settings on your phone or a piece of paper and store them safely somewhere. This ensures that undervolting in the future is mostly a stress-free process.

Undervolting isn't as easy as you think

At first glance, it might seem like you just need to adjust the voltage sliders to get your desired result, but it's not that easy. Sure, you won't risk damaging your components by lowering the voltage, but system stability can be a pain to deal with. I've dealt with so many BSOD errors and learned this the hard way. The benefits of undervolting depend heavily on the mistakes you avoid along the way. It requires patience, extensive stability testing, and constant monitoring of your PC's performance for days. When done correctly, it can truly be a rewarding experience because your PC runs cooler and more efficiently, potentially extending the longevity of your components.