Make your CPU more efficient and faster – Power limits and undervolts

AMD and Intel have never been as competitive as they are in history. In our latest Processor Best Buy Guide, their top models differed only 3 percent in the Performance Score. Only good for us consumers, you would think, but this fierce battle has a dark side; the latest cpus consume more and more power and are therefore getting hotter.

In this how-to I explore the possibilities of making your processor work more economically and show you the consequences for performance, power consumption and temperatures. I do this using two of the most consuming consumer processors at the moment: the AMD Ryzen 9 7950X and the Intel Core i9 13900K.

The two processors I’m taking on this challenge with: the AMD Ryzen 9 7950X and the Intel Core i9 13900K

Powerlimits an undervolt

The power consumption of the processors mentioned is of course pure madness. In our measurements, AMD’s top model consumed more than 226W, while the Core i9 13900K far exceeded that with almost 339W. A moment of realization for those who have been around for a while in the hardware world: that is both even more than the much ridiculed FX-9590, AMD’s ultimate attempt to make something of its failed Bulldozer architecture.

Later in this article you will see that the effect differs slightly between AMD and Intel, but in general there are two basic principles to make the processor more efficient. The first of these is tweaking the power limits, or the amount of power that a CPU can use continuously. The other option is undervolting. Whereas with traditional overclocking the voltage was increased to enable higher clock frequencies, with undervolting it is actually lowered to make the CPU more efficient.

Setting a power limit limits how high the processor can clock; the automatic boost algorithm is more likely to hit a wall. Undervolting, on the other hand, does not necessarily lead to lower clock speeds. In fact, because more room is created in the power budget in combination with a power limit, an undervolt can actually lead to higher clocks in practice. However, if the voltage is too low, the processor can become unstable, so the stretch in this is not great and can vary depending on how ‘well done’ your individual processor is.