The 12900 variants have 8 high-performance cores and 8 high-efficiency cores. The 8 high-efficiency cores add little to the multicore performance. In fact, on Windows 10 this can hurt performance in some situations because Windows 10 is not aware of the different CPU types. Thus 12900ks being 94.6% faster doesn't seem unreasonable.As for multi score i would expect 12900k/ks to be approx double seeing as it is running double the cores. This is just logical . Then if you take into account the fact that the p cores are a newer generation and faster and the e cores are a little slower it still balances out about double! Its Logicical !
But multicore vs 12900k/ks is a completely different price and product segment.
I don't know how you have come to compare 12900ks to 5800x3d for multi core ? Its just not logical.
Its all about gaming for 5800x3d