Intel Core i9-12900K at 125W

What happens when power is dialled down?

Much has changed in the desktop PC landscape during the preceding week. Intel has come roaring back into the performance game with the release of 12th Gen Core chips known by the codename Alder Lake. Offering a mix of Performance and Efficient cores – the first time this has happened on desktop – the headline Core i9-12900K benchmarks well against AMD Ryzen competitors.

Yet for all Intel’s myriad advancements, comprising process, architecture, and implementation, the chip giant needs to run at elevated power budgets to dethrone AMD, and this is where comparing rival chips on an apples-to-apples basis becomes tricky. You see, Intel mandates a Processor Base Power (PBP) of 125W, which is close to the 105W prescribed by AMD. However, crucially, Intel also has a Maximum Turbo Power (MTP) of 241W for the same chip.

The MTP figure is the one enthusiast-orientated motherboards adopt naturally, with the premise being one of extracting the most performance out of the chip whilst still running within Intel-mandated specifications. Consider MTP to be automatic overclocking overtly encouraged by Team Blue.

Cranking up long-term power offers little scope for enhanced single-thread performance – running a few threads doesn’t tax the overall power budget by a discernible degree – but does mean Core i9-12900K benefits from running at higher multi-core speeds.

As we know how the chip reacts when operating at 241W, an interesting question is what level of performance is achieved if limiting power to 125W, which is what large OEMs such as Dell and HP are likely to do for their mainstream systems equipped with rudimentary cooling.

Thankfully it’s pretty straightforward to limit the chip’s total power to 125W. Intel’s useful XTU utility provides excellent control over various processor characteristics, including fine-grained power, as illustrated above. The application correctly identifies the reduced power limit as the key inhibitor of performance, and chip smarts dial down all-core frequency from around 4.8GHz to 4.3GHz, alongside lower voltage.

Exactly how the 125W limit affects performance is evaluated on an app-by-app basis, so without further ado, let’s run our Core i9-12900K in this more frugal power state and compare against previously tested chips.