The last Intel CPU I bought was an i5 Kaby Lake CPU for my son's PC, and the cooler that comes with the newer CPUs is pretty much useless. It's all aluminum, and doesn't do much of anything besides constantly spin up and down, and keeps the CPU from throttling (at least the i5 CPUs). It would get into the upper 70s when he is gaming, and its noise profile is not pleasant. I ended up replacing it with a Noctua NH-U12S.
70*C during gaming doesn't sound bad. It's far from CPU limits. Why do you care?
The stock fan is clearly not the best out there, but it's very nicely set up. It's really quiet at low RPM, so it's not a problem in idle and low load (like browsing etc). Under load (especially for 35W+ CPUs) it gets a bit loud, but it manages to provide the guaranteed performance even from an 8700.
When you think about it, it's actually quite an achievement and a surprisingly user-friendly fan for the price. You'll have trouble finding something better for around $10.
I saw a review at Tom's where the stock Intel cooler that came with the i7-8700 (non K of course) wasn't sufficient enough, and affected performance by reducing the boost speeds.
It doesn't. The stock fan is only guaranteed to support stock clocks. Boost can, and usually will be, affected. A safe approach is to get a fan designed for twice the TDP of CPU.
In fact there's a very decent article describing the issue on anandtech. ;-)
It actually did a half decent job on my old G3258, was able to keep it stable at 4.5GHz, but thats a 2C/2T CPU. I wouldn't dare use it except as a last resort on my 8700K though, even at stock!
I used to have a couple of Dell SFF rigs with Haswell era chips and you are right, the custom HSF designs are better than the stock Intel HSF, that is for sure.
8700K is too much for the current stock cooler. 8700 is OK (sans the boost).
Intel will most likely have to design a new solution for upcoming 8-core (non-K) CPUs.
There's no way a stock cooler (or even a 3rd party one) could be better than custom solution (of similar size and cost). That's the problem with universal design of home-built PCs. CPU and GPU air coolers are designed to push hot air as quickly and as far as possible, but they're still in an enclosed box.
Airflow in a case is never optimal and suffers from massive turbulence.
If you have a window in your case, here's a nice experiment: attach a few bands (or pieces of paper) inside and look what happens.
Ideally, they should always move in the same direction (just by different angle depending on load).
If you open a Dell case, you'll notice they use fairly simple and cheap radiators and fans. But the whole system is designed to utilize them as good as possible.
Few years ago I had a Cooler Master case which included a simple air tunnel. It fitted Intel fan perfectly and meant that CPU was cooled by air coming from outside the case. This simple plastic tube lowered temperature by at least -5*C.
I really wish we could get some case-specific cooling solutions...
IIRC, Intel still ships at least 4 desktop coolers. The two standard ones, one of which has a copper slug (95W?), one of which does not(65W?). They have the bigger cooler, the TS15A, and they have the liquid cooler, TS13X.
Intel makes a few coolers, but currently only one is bundled with CPUs. They used to bundle 2 variants depending on TDP (AFAIK until Haswell) - one had a copper core.