The arstechnica numbers surprise me, given the sheer difference between the Ryzen 7 1800X and the Threadripper 1920X compared with the 1920X and the 1950X; either you've reached more or less peak parallelism by 16 cores, or the larger L3 cache and quad-channel memory makes the difference. Or something's changed in the benchmark setup (be it the compiler or whatever) since the 1800X was done.