Could've sold my 3900X for 850$ when I found out I was able to get it to 4.2GHz at 1.25V. Make dat 300$ profit (take away taxes...). But I fell in love with it and decided no one is gonna touch my baby but me.
If every single 3950X they tested can maintain 4.00GHz all-core under their testing criteria, and a majority of them can hit 4.10GHz, it seems a bit silly to pay a $100 premium for the bottom-of-the-barrel, lowest-8% of chips when there's at least a 92% chance that one bought at random will be better. I suppose the 3950X is hard to come by at the moment, and markups by small sellers are to be expected, but just to get a guaranteed average-performing chip, they charge a $400 premium. I guess if they didn't, 3rd-party resellers might buy them up and do the same though.
Also, with a less than 4% all-core overclocking difference separating the best-performing chips from the worst-performing ones, it all seems a bit pointless. And going by their data, chances are that a 3950X bought at random will manage 4.10 GHz under their test criteria, so the best-performing models they sell only manage a little over 1% higher clocks than average, but cost twice as much as MSRP.
And performing an all-core "overclock" on the 3950X seems a bit pointless in general, unless perhaps a system is only used for heavily-threaded workloads that utilize all cores, and lightly-threaded performance doesn't matter. Otherwise, you're trading a notable hit to lightly-threaded performance for minimal gains to heavily-threaded performance.
Silicon Lottery must have got a rather poorly binned lot of chips ... most reviewers and enthusiast anecdotes got higher than theirs ...
But I suppose more than ever, stability has a lot of grey area. What's perfectly fine for games, youtube, short benchmarks, browsing, might not be ok at all for 2 hours of 3D rendering ...
On my Ryzen 1700, I can game for hours at 3.95 and never have a hiccup; but for 3D work, I have to go down 3.8 else I risk a crash after a couple hours of rendering.
I'm sure Silicon Lottery is playing it on the very safe side here, since they have a guarantee to uphold.
Not worth the premium ... you need at about 4.2 on 3900x/3950x to get better performance over stock in lighter threaded situations anyway, and the all core boost is pretty good on the Zen2 parts. Best to leave at stock and tweak clock, timings, and sub-timings on RAM for Ryzen.