I'm using xfx 7900 xt on a i7-2600k with no overclock and getting 40-60 fps scaled to 4k.

The bus is 2 generations old, and my Thermaltake 700 watt power supply is basically inadequate, at least without using Molex's to increase the power (the 6 pin connectors are in serial instead of separate, wtf?) 

Undervolting and overclocking gets me to just about 60fps consistently.

I've been using a i7 2600k for years in my VR game pc pared with a 1660 and no trouble

I still use the 2700K, although a new Alder Lake is going to be ordered in the next few days. It is still brilliant. Initially paired with a 580, last year I put  1660 Super in there and it really still flies. Apt really, as the main use for the old PC is Microsoft Flight Sim 2020 and that is a real resource hog. With some quite high settings, it runs a 1440p screen and three 1080 screens at an average of 40 to 45 frames per second. It has been wonderful to me and will still run all of my mapping and planning programs in its retirement. If a 12900K can last half as long and be half as good as Sandy Bridge, I will be well satisfied.

i-5 is better than older AMD

I'm still using a 3770k @4.2ghz, 2400mhz RAM and have a RTX2080 with it. CPUs of this era are still fine for 60fps gaming, the caveat I've found is that RAM speed really has an impact on these older platforms. Sandy Bridge IMC is only able to run upto 2133mhz RAM but at the time 1600mhz was the standard pairing. If you still have a 2600k swapping out that slow RAM for some low latency 2133mhz sticks will really help with the 1% low frames and micro stutter.

it's ukranian, please don't insult, especially when Russia and Ukraine is at war :(

Sorry but you are delusional if you think you're going to get a smooth 60 FPS with a 2600k in the majority of modern demanding games. I had a 4770k that was overclocked and even three or four years ago there were games where that could not maintain 60 FPS. For instance watch dogs 2 would dip down into the upper 40s in spots and those same spots were nearly a 100 FPS with a 9900k. And as many people will point out even if you do get 60 FPS it is absolutely not going to be smooth because that CPU is going to be completely maxed out. Bottom line is you would have to be an idiot to go out and spend big money on a high-end card to pair with that old CPU.

From personal experience, having an older CPU can produce a decent overall FPS number, but smoothness can be the killer.

I played a lot with a 3070 and 4790k, and found I got a lot of frame hitching and stuttering in CPU heavy titles, even though my average frame rate was ok. I had to cap at 45fps in Cyberpunk to get a smooth(ish) experience for example.

When I moved to a 5800x, things got a lot smoother

I just retired my I7 2600k. Reason being was too have the new mobo architecture. That said, I never had issues with it and I had it for 10 years. It did steuggle with more CPU intensive games, but in graphic heavy ones it struggled none.

I'm using a Xeon 5670 in one Pc along with a GTX 1070. It's good enough for 1080p gaming on a 60Hz monitor. 

GECID.com is not russian outlet! It's Ukrainian. Check info before posting.

Playing at 4K or 1440p also takes the cpu out of the equation, mostly.

playing at 50Hz with v-sync locked can also help in some cases for a smoother overall experience when the CPU is old.

 :) I can confirm, this is my CPU atm. i bought an i5 2500k in 2013 and upgraded to a i7 2600k for 20$ 5 years ago..8 threads make a huge difference from 4 threads, but apart from that, the i7 2600k is flying still. I had it OC to 4.5G, atm it's only 4.0G and working fine, T around 65C, I pair it with an MSI GTX1060 6GB Gaming X OC at 2GHz and DDR5@4x2250, hyper stable. It's a perfect match bw GPU and CPU + 16GB DDR3 1866 and a triple monitor setup 1080p. Do I need a faster CPU? No. A faster GPU ? No, 60-100fps in most games. The only thing I would like is M.2 SSD interface instead of SATA. Apart from that it's utterly stupid to spend $$$ on a new system for a 10-20% gain.
Ah and I disable Spectre and Meltdown mitigations ;-) it's a stupid fix for system servers, no risk on a personal machine and that's 6% or so extra speed (measured it eons ago...) :p

To the author of the article, there's no i5 2600k. I think you meant i7 2600k.

It just goes to show that the CPU is not the bottleneck most of the time, and 60 FPS is not particularly hard to reach.

If a game was designed to run on the PS4, Xbox One, and older desktops, a decent quad-core will get the job done. Even a dual-core 3000G with a discrete GPU can reach 60 FPS in some games, although it will also have stuttering and bad results in certain titles.