Reason being that when you have a 7950x3d (and I assume same for 9950x3d), when you spin up a game, the scheduler nearly disables the non-3dvcache cores, so that the game doesn’t try to use both CCD’s. In some early cases the mixed ccd does not disable the non-vcache ccd and you get worse performance. This is mostly no longer the case, but if you don’t need every last ounce of frequency on those higher frequency/lower cache parts then why not?

An epyc that has Zen5 x3d ccd’s for all…probably cost a lot, but 128 cores (16ccd’s) …that would be 1.5Gb of cache for a single chip…databases would scream with performance.