The tests involved Intel Core i9-12900K and Core i7-12700K and Core i5 12600K processors, which showed the same tendency to decrease performance when using inexpensive motherboards. During the tests, it turned out that the reason lies in the mismatch of the power subsystem of such boards.
Low-end motherboard models are not able to deliver the required power of 135 W for a long time, and the minimum Power Limit 1 value required for their normal operation is 125 W. At the same time, they consume much more under load.
A decrease in performance was noticed when switching processors to Boost mode. Intel Core i9-12900K showed a drop in performance by almost 30%, mostly it kept within 25-30%; Core i7-12700K lost 21-25% performance. The younger model – Core i5 12600K lost 7-9%.
As noted, the best decision when choosing a processor will be a motherboard based on the Intel Z690 chipset with a “10 + 1 phase” power supply, DrMOS integrated circuits and a current of 50 A.