The 3900X is held back by the "shitlet". One good chiplet for high boost clocks, and one shitlet that's probably no better than a 3600 or 3600X to get that core count up. The shitlet holds back all core OC. From what Gamers Nexus was achieving on their 3950X (4.4 stable and they said 4.5 looked possible as stable with some more tweaking - they said it was ALMOST stable at 4.5), it's possible both chiplets on that are pretty golden. Might get better OC results. Then again, perhaps not - perhaps GN just got lucky.