You're counting physical cores but the CPUs are hyperthreaded.
Divide the L3 cache size by 2M and that's the optimum number of threads to run.
Any more and total hashrate starts to drop.
The question was answered early on in this thread.
I'm not following. What does HT have to do with this? It's never used for mining with E5 v1/v2 - either it's disabled in BIOS, or the miner's threads are bound to the physical cores. Of course I'm "counting physical cores", cause that's what matters in RandomX mining with these Xeons. Every single E5 V2 CPU in existence has 256KB of L2 and 2M+ of L3 per physical core, so that's how they're used for mining - with the number of miner's threads equal to the number of cores. All the benchmarks out there are like that, number of threads = number of physical cores. I don't understand your post and my question was not answered in this thread, it has nothing to do with HT whatsoever.