Hey ChornyRussian,
As someone who was in the same situation, sorry for all of the people telling you that this is a waste, if you are going for an overkill build, I absolutely applaud you.
I personally built a completely overkill build a few weeks ago on the Zen 4 platform the day the 4090 came out. The specs are as following:
ASUS TUF X670E PLUS WIFI
Ryzen 9 7950X
RTX 4090
64GB DDR5 @ 5600Mhz
2x Samsung 980 Pro
Now, I mention all of these things because a lot of these details are very important. Firstly, during the first week after completing the build the PC was plagued with stability issues, extremely long boot times (DDR5 memory training), and random shutdowns. However, all of these things, at least for this particular motherboard, have been solved with a BIOS update (more detailed info at
https://forums.tomshardware.com/thr...-whereas-7900x-is-fine.3779906/#post-22836768 where we worked through this issue) , as is the case with many other x670 motherboards. After the BIOS update, boot times are exponentially quicker and zero crashes whatsoever. This is all to say that if you want to go the AMD route at least, be wary of issues on the new platform, and do some research on the motherboard you are looking to use to make sure it either does not have these issues or has a BIOS update available that addresses them. Likely, most will eventually if not already.
However, after all these stability issues, I am sure you will also deal with some on the Intel side of things as well, so let's move into performance.
I think that the biggest deciding factor for you should be what you intend to do on your rig.
If you plan on only gaming on this build, I would probably suggest the 13900K or 13900KF as historically they have been the better option in terms of gaming performance, especially in single-threaded games or games that are not optimized for high thread counts. However, if you also plan to do work on this build, or you game in addition to streaming, using browsers, or have any other open programs, then I would probably recommend the 7950X.
Now, there is also the issue of power draw. By default, both of these CPUs are pretty power hungry, but from my understanding, the 7950X can be tamed significantly more by undervolting while barely losing any performance, and by default offers substantially more performance per Watt. In my brief testing, I threw a -0.05v undervolt (no overclock) on my 7950X and achieved a -11C ((5C to 84C) difference under full stress load (CPUZ stress test) using my LIAN LI 360mm AIO, all while maintaining the same performance. I am sure more tuning could likely achieve better results.
Of course, all of this is coming purely from the AMD side of things, as I am definitely not spending another ~$6K on an Intel rig as well, but I personally find the AMD build to be extremely versatile, and that is coming from an Intel fanboy of about a decade.
As for everyone saying that both of these CPUs are overkill. Consider letting OP have a little fun. I personally find ways daily to max out both the CPU and GPU in my gaming and workstation use cases. For example, Cyberpunk 7680x1440p (3x 1440p monitors) @ 240hz, albeit with DLSS, pushes both pretty hard, but results in an insane gaming experience. Fortnite does hit 1200+ FPS (no DLSS, lowest settings), which is a bit overkill, but Call of Duty Rebirth only hits about 250 FPS (no DLSS, absolute max settings) and appears to be more CPU limited than GPU (it is, of course, a 4090). I will also throw into the mix Blender rendering, which performs insanely well on the 7950X, even more insanely well on the 4090, and ludicrously when using both.
So, OP, I wish you the best with your future build, and in my personal opinion, you probably will not go wrong regardless of the direction you go in.