If you're not undervolting your CPU and GPU, you're missing out. Years ago, overclocking was all the rage. Even a moderate overclock could represent big performance gains, but as time has gone on, and Intel, AMD, and Nvidia have pushed their silicon to its limits, overclocking has represented less and less potential performance. PC enthusiasts have corrected course and focused their attention on undervolting in turn.

Undervolting aims to make your PC run more efficiently, delivering the rated clock speeds of your components while drawing less power. In theory, an undervolt should offer the same performance with better efficiency, but understanding how undervolting works can actually net you more performance out of your components.

A quick primer on undervolting

It's a misunderstood tool, so let's set the record straight

Let's make sure we're all on the same page. Undervolting is usually served up as the antithesis to overclocking, but that misses the point of what undervolting accomplishes. Overclocking is concerned with pushing your clock speed higher than rated specs, regardless of the cost. You pay the cost of higher clock speeds with increased power draw and more demands on your cooling system. Undervolting doesn't have that same cost. There are trade-offs, but undervolting is just concerned with optimizing how much power your CPU demands.

It works across the voltage/frequency curve. For any given clock speed, your CPU needs to draw a certain amount of voltage. AMD and Intel define the voltage/frequency curve, and it's usually conservative. That means at lower clock speeds, AMD and Intel usually feed the processor more voltage than it needs. That way, it can have some tolerance in silicon quality while ensuring that all CPUs remain stable. Undervolting exploits that tolerance by lowering the voltage for a given clock speed, attempting to push the voltage as low as possible while remaining stable.

In short, undervolting looks to answer one question: for a given frequency, what's the lowest amount of voltage my CPU needs?

What you do with an undervolt is far different. There's a range of clock speeds and frequencies, so the goal with one undervolting endeavor may not be the same as another. Maybe you're just concerned with optimizing power draw at lower clock speeds, or maybe you're in a thermally constrained environment where an undervolt allows you to reach maximum boost clocks. It depends on your setup and needs.

Undervolting can improve performance, efficiency, or both

It is what you make of it

Undervolting can improve your performance and bolster your efficiency, and in an ideal world, it can even do both. The core of undervolting, however, is to reduce temperatures. If you're able to achieve a certain clock speed while delivering less voltage, your CPU will run cooler. Maybe that's the end goal of your undervolt. For instance, I have an undervolt running on my Ryzen 7 9800X3D in my small form factor PC, and I use it simply to keep temperatures in check. However, you can also leverage an undervolt to push clock speeds further.

You don't often see an undervolt before an overclock with a CPU, but it's still possible. If you lower the voltage across the frequency range, that theoretically means you're able to push clock speeds higher before hitting a power or thermal limit. Modern CPUs just have very tight margins for voltage when it comes to stability, so there usually isn't room to undervolt for a frequency win. You'll more commonly find an undervolt before an overclock with GPUs, where the voltage ranges are more generous. For instance, Nvidia's Ampere architecture delivers high voltage over the frequency range, and you're usually able to apply both an undervolt and an overclock for better performance at lower power draw.

Temperatures play a critical role regardless of what hardware you're trying to undervolt. Since the goal is reducing temperatures, you can end up with higher performance after undervolting your hardware if you had previously hit a thermal wall. The idea behind undervolting, however, is to not reduce your performance at all. It's simply to deliver the same performance at lower power, improving efficiency.

You run into performance drops when dealing with larger compromises to power consumption. With AMD's Precision Boost Overdrive (PBO), for example, you can undervolt with Curve Optimizer as well as set lower power limits. This will usually net a slight reduction in performance for a large improvement in efficiency. Undervolting on its own shouldn't reduce your performance. If you push the voltage too low, your PC will become unstable instead of dropping performance.

The silicon lottery plays a big role in how far you can push an undervolt

Don't expect every CPU or GPU to work with the same settings

Undervolting is worth it for performance and efficiency. By how much? That's where things get tricky. Different components will take to an undervolt differently. You see large changes between architectures, but you'll even see changes between two components that carry the same name. For instance, AMD's Ryzen 7000 and 9000 chips generally handle undervolting well, while Intel's 14th-gen CPUs will become unstable with even a moderate undervolt. Beyond that, two chips within the same range can post slightly different results. One Ryzen 7 9800X3D may be able to remain stable at lower voltages than another.

How far you can push your undervolt, and how much you're able to get out of it, not only depends on your specs, but also the specific chip you have in your PC. It's the silicon lottery. Just as some components can handle more extreme overclocking settings, some components can handle more extreme undervolting settings.

Should you undervolt your CPU and GPU?

Short answer, yes. Long answer, also yes.

Modern CPUs and GPUs have a lot to gain from undervolting, and I'd argue that they have more to gain from undervolting than overclocking. That's especially true among CPUs. AMD and Intel have designed algorithms that essentially allow your CPU to overclock itself if power and thermal conditions allow. With that setup, the CPU usually draws more voltage than it needs across the frequency range, so you're able to get thermal benefits while maintaining performance with a moderate undervolt.

GPUs are in a slightly different camp. Clock speed is less of a factor in overall performance with a GPU due to the heavily parallelized architecture, but in general, you're able to push slightly higher clock speeds out of a GPU with a moderate undervolt. Since GPUs have their own cooling apparatus, and they usually don't run near maximum operating temperature, you can push an overclock much further than you're able to with a CPU. As is always the case, though, it depends on the specific hardware you have.