I5 12600kf

[Saulo]

I5 12600kf só atinge 4.50 ou 4.20 ghz. Não chega a 4.9 ghz. Novo!

Placa mae msi pro b760m-p
Comprei outra placa mãe nova msi b760 gaming Plus WiFi. Ambas mesmo desempenho

[AlHill]

4.9GHz is the processor's Maximum Turbo Boost frequency.

https://ark.intel.com/content/www/us/en/ark/products/134590/intel-core-i5-12600kf-processor-20m-cache-up-to-4-90-ghz.html

Information provided by @n_scott_pearson :  You are only going to see boosting to this frequency when (amongst other things) your processor has the thermal headroom and only a single core is active. If (amongst other things) the processor is too hot or more than one Core is active, the maximum frequency possible will be lower.

I said 'amongst other things' a couple of times. This is a complicated subject and, if you really want to understand it, you are going to have to spend some time reading about it. As a starting point, try these resources:

• What is Intel Turbo Boost Technology and How Does it Work?
• My Intel Core Processor Does Not Reach the Maximum Turbo Boost Frequency
• Frequently Asked Questions for Intel Turbo Boost Technology
• Frequently Asked Questions About Temperature for Intel Processors

Doc (not an Intel employee or contractor)
[If you find any Intel driver you might need, download and save it now.]