Hello, i did more testing on these, it is a very complicated matter.
Maybe overcomplicated.
Overclockers have a spreckity lingity on "boosts" and "cooler points" and "stress" and one hundred finer points of tuning, which loses me.
I see the language all has its purpose if you are designing and marketing gaming kit, but Intel/Asus (at least) also seem smart enough to realize that a successful product will package all these details into an automated mgmt system that lets the parts run out-of-box with a claimed performance, and it all just works.
When was the last time you read anywhere that "my CPU completely died". It's very uncommon parlance outside of extreme clocking. OTOH What happens all the time is the overstressed CPU calculates the wrong answer and crashes, or corrupts some bit of data which these days of mass media you might not notice. The fact is that computing is generally intolerant of wrong calculations, so when it calculates wrong you have to make an adjustment, and Intel has got exceptionally good at this balancing act with superb quality control and attendant binning that lets them offer rich spread of SKUs based on the finer points of the outputs of their fiery cauldrons.
I see there's a history of lingo for tweaking what was once the province of super nerds, OC tweaking is now a routine sector of market: K series parts with well-understood physical limits set in boards with all manner of adaptive juju (Asus AI Extreme blah blah) to run at those limits.
I get that the kit lexicon is very rich with decades of OC tweaking experience that got the market here. I get it's to the taste of nerdy asperger's cases (like me) and that bragging sells kit. Moreover, everyone who designs this stuff actually has to think in these crazy terms to make the adaptive mgmt work, especially given the major premise of letting ignorant end-users arrange the electro-thermal quality of parts and configuration. I get all this.
But there's a paradox: Apparently with this 10900, THEY FIGURED IT ALL OUT. We can all live now in a happy land of flowers and rainbows because unlocked parts are just another part with a 5% build cost premium.
From my point of view of my simple experience with one late-model Asus gaming board and 10900K, the kit does the right stuff to within a hairs width of it's claims: it runs sustained at 4.9 Ghz all core on media transcode, it never crashes, it only calculates wrong when I force it by noodling over certain incantations to push it past spec limits, and it benchmarks in agreement of the experience of literally thousands of other users. All the while in a curious absence of din of complaints that "my CPU just died."
The only bugaboo I've read about (never seen myself) is the AVX workloads are an cliffs-edge case for peak unlocked power, and Intel community acknowledges this edge and provides tools to step back from it. But that's for sciencey workloads which I'm not doing, nor is anyone else I see here.
WRT stress, there is endless handwringing over the additional cost of unlocked parts, but this usually amounts to less than 5% of a premium build. And the people who talk about it most have 3 or 5 prev generations of kit on hand! I guess fretting over the price like haggling at the middle-eastern bazaar; something you are just expected to do... Except — amazingly — the bazaar sells practical magic beans and flying carpets! Remember, this years rug patterns are limited stock. Buy now.
There's also endless handwringing over voltages and temperatures. Well these go hand-in-hand with frequency. The kit is designed to run at 100C or less and will do so all day. The mgmt will control the freq and volts, and the device has a rev limiter. So you just have to feed it proper power and arrange to move 300W of heat across a junction the size of a dime.
What's complicated about that?
As to the picking and choosing and fussing over incremental differences between parts: everybody comes to same conclusion: the xx700 series are always the price/performance sweet spot. Go lower if you lack cash. Go higher if you are workload constrained or want bragging rights.
As to which mainboard supplier is not dorking up whatever generation with some quality control or firmware oversight, it's a rotating circus. I put my money on Asus, but it's a religious matter.
That's my story and I'm... nvm
Re cash handwringing: In states, 10850K is $450. 10900K is $500. Not going to make or break a build. For the 10% cost premium, you can expect a 2% performance premium. So done and done.