Hello, I'd like to share with you on how you can improve the efficiency of your i9 12900K tremendously.
It's going to work on any CPU really.

Step 1 - Undervolting

1. Enter BIOS

2. Go into CPU settings or advanced CPU settings

3. Edit Dynamic VCore voltage, set it to -50mV (-0.050V)

4. Keep benchmarking it and progressively go down by -10mV each time, or immediately go up to -100mV and work your way down if it's unstable (or up, if it's good!)

Step 2 - Power Limit

1. In BIOS, find Turbo Power Limit option

2. Set your power limit to 175W (the max wattage of this CPU is 241W natively)

Step 3 - Adjusting fan curves (optional)

1. In BIOS, enter the fan settings and move your fan curves down.
   It's likely that the fans can spin noticeably slower, while becoming only slightly less efficient at cooling your CPU.

Step 4 - Benchmark, benchmark, benchmark!
This is the most important step! You need to test your CPU in a benchmark, for example Cinebench 2024, to make sure that it's stable and that it performs well!

On my unit, I went from, at default settings: 95C, 1650RPM, 435W (combined power draw including monitors) and 1537 score.

To undervolted, power limitted and adjusted fan curves: 75C, 1440RPM, 360W (combined power draw including monitors) and 1531 score.