As the other poster stated the S in the 9900KS is different. In this case the 9900KS actually draws more power with a higher base and boost clock than the 9900K.
This is a good point, however a real test would be to compare the 3800X vs. the 9900KS with JEDEC memory clocks, so 3200MHz for the 3800X and 2666MHz for the 9900KS and while there would be a difference with a ~500MHz bump for the 9900KS and a ~350MHz reduction for the 3800X, I don't think it's going to make up the ~8% performance difference. Zen was always designed for scaling out to many cores, so it's not surprising that even at a single core disadvantage, the Zen-based parts perform better in multithreaded workloads.
Wow, a person who would use a 9900K with 2600 ram has appeared. Never thought I'd see the day. I would suggest people to compare them with equal rams that run at 4400 mhz or something. You can buy decent 4400 mhz ram for like 150$ and it's a no-brainer compared to buying 3200 mhz if you have a top-tier CPU. You pay 75$ more and you get 10% more FPS. Maybe you're also the kind of person to tell me that paying double the price for the ram is not worth the 10% performance increase?... When the overall cost of a PC went up 3%.
But even with that handicapped memory, 9900k would still outperform. Going from 2133 to 2666 would improve FPS a lot.
View: https://www.youtube.com/watch?v=-m692eBH2Jw
-> see the FPS for 2133 vs 2666. It would scale a lot better with a 9900k but I couldn't find a video or benchmarks for that, the test uses a 8600k which is less memory dependant(the more CPU can output, the more ram bandwidth it needs to feed it). Even so, the difference in framerates is massive. Going from 2133 to 2666 shows a consistent 10-15% difference. You could probably have at least 15-20% difference with an overclocked 9900k instead.
So 3200MHz for the 3800X and 2666MHz for the 9900KS and while there would be a difference with a ~500MHz bump for the 9900KS and a ~350MHz reduction for the 3800X, I don't think it's going to make up the ~8% performance difference.
Your ridiculous claim doesn't seem to hold up. Just the difference alone in speeding up 9900K from 2133 to 2666 is more than 8%. And you wouldn't handicap 9900K(F? S? any 9900) chip with a 2666 memory either. You most definitely want a blazing fast memory with that CPU. Even 3200 mhz is like 65$, and I suggest getting at least a 4000 mhz memory for 9900k(the ram gets crazy expensive at high end, but you can still find 4400 at decent prices). I've bought myself a 4400 19-19-19-39 ram for $160, seems like it's sold out now. But you can still find other decent deals for fast memory ¬4000 mhz or higher. $160 for nearly equal performance is a killer deal compared to something like this
https://www.amazon.com/Kingston-Tec...s=4600mhz&qid=1563932356&s=electronics&sr=1-3