I did just swap the BIOS prior to CPU swap but forgot to remove AMD drivers and ran into problems on windows boot. Had to boot in safe mode and uninstall. Then it started normally. Now I'm trying to settle Infinity fabric with memory clocks (1800/3600Mhz).
Temperatures are SCARY. Idle around 50C, haven't dared running benchmarks yet. CPU boost goes to 4500Mhz single core and 4150Mhz all-core. But once in cinebench I believe this will be lower when using AVX.