@jq0213
What is your Cinebench R23 score? Approximately 17600 is a normal score for a 12600K.
Have a look in the BIOS. What are your turbo power limits set to?
A lot of people use an all core overclock on the 12600K when they are installed in an unlocked Z series motherboard. Your results might be less if they their computers are overclocked and your 12600K is not. The B660 boards do not support any overclocking.
The B660 boards have another feature called Intel Undervolt Protection. This feature is broken in my opinion and can cause CPU performance to be cut in half. Run ThrottleStop 9.6
https://www.techpowerup.com/download/techpowerup-throttlestop/
Post a screenshot of the FIVR window. It will show if UVP is enabled. If ThrottleStop shows Undervolt Protection, check the BIOS to see if this can be disabled.
If your Cinebench R23 score is way off, post some ThrottleStop screenshots of the FIVR and TPL windows so I can see your settings. Newer games seem to be using a lot more CPU resources.