Grats on a new space heater. :)

A space heater that is excellent for games

And will run very efficiently with a bit of tweaking and a power limit that won’t impact performance.

Congrats Op, have fun with it!

you got it for a decent price so id say no overkill is not a bad thing it means if you look after it you wont need to replace it for a long time

I don’t think there are any sub $100 CPUs that could compete with a 12900k at 4K.

Just enjoy it and don’t let it bother you.

sub $100 CPUs that could compete with a 12900k at 4K

depends entirely on the GPU, no? Anything can match a 12900K considering it won't be the limit at 4K most of the time.

CPUs last a very long time and as the years go by, system requirements will start to rise. Your i9 will be able to push some GPU upgrades without you needing to get a new CPU. It's a good long-term investment, so don't wallow. Enjoy it. In a few years, you'll be very happy that you got it for a good price.

If you'll have production workloads that will benefit from the CPU then you can justify having an overpowered CPU.

If it's just for gaming though, it's overkill in terms of spec. However, when we criticise people who overspend in their CPU, we criticise them for that, overspending, not overpowering.

Having extra power is not bad, if anything it's better. It's just that some people choose to spend $500 on the CPU and $500 on the GPU, when they could be spending $250 + $750 and have a system much much better suited for gaming.

You spent $265 on an overpowered CPU. You did not overspend, at best you could skimp $100 if you wanted to get a budget CPU, which is probably not enough for you to get the next GPU.

I'd say you made the right call. What GPU do you have though?

As a fellow 12900k owner with a 4k monitor, you're gonna be just fine, I've never run into a single issue