I know why I want AMD parts and that is because of ECC memory support but this article doesn’t even mention it.
If you want to game @ 1080p and do mostly single threaded work (without parallelism), this CPU is not for you. If do a lot of single-threaded jobs in parallel (for example, gaming + being a server or gaming and streaming) or anything multi-threaded, this CPU destroys the 9900k, while being just a bit weaker when doing just one or two single-threaded tasks.
Regarding the geomean, they clearly state that their benchmarks prioritize multi-core benchmarks: "This metric also puts the 3900X above the 9900KS, because despite the 5.0 GHz all-core on 8-cores, moving to 12-core and 16-core at almost the same performance per core gives more of an advantage in our test suite's MT-heavy workloads."
They're not hiding behind anything. Everything is clearly stated.
I was responding to:
"Also not sure why they include the 3-d particle thing without AVX"
in which the op was not clear which AVX instruction set they were referring to. It seemed to be a difference benchmark from the one which had avx-512 disabled, due to the word "also"
If I'm using some of my cores to run AVX-512 code in the background, it's going to drastically slow down everything else I'm doing.
This can be a significant issue even if you are only running the one task. If you have intermittent AVX-512 code, any time any one of the cores starts running that code, everything else also slows down too which can result in a net loss in performance. Even if you only ran a single core and it used AVX-512, this could still be the case because it takes precious time before and after to lower and raise the clocks that much and everything else runs slower that whole time in addition to running slowly while the AVX stuff executes.
1) Intel has per-core frequency and voltage control. To the extent that AVX-512 inhibits higher clock speeds that effect is local to the core or cores on which AVX-512 is active, and only those cores.
2) Not all AVX-512 instructions have this effect. `vpermb` for example does not.
3) Some other AVX instructions that are not AVX-512 have this effect. Also anything else that makes a core hot has this effect.
4) Most importantly, Cannon Lake microarch and later don't have this effect.
If you look through the results, the things most people want to do with a computer, like browse the web and start their applications, are noticeably faster with the Intel i9-9900K at half the price. And the only game where the CPU makes a difference in these benchmarks is also a lot faster with the Intel part.