Just upgraded to a Ryen 9 3900x and after fresh installing windows with the latest GPU drivers and chipset drivers and motherboard BIOS it keeps crashing with WHEA_UNCORRECTABLE_ERROR while playing games.
The GPU and CPU are both at stock clocks, have never touched OC with them.
AMD Ryzen 9 3900x
AMD Radeon VII (Radeon Software Version
16Gb Corsair Vengeance LPX DDR4@3000Mhz
EVGA 850w PSU
ASRock X470 Taichi (BIOS Revision 3.43 - latest)
Another issue that I see is that in AIDA64 stress testing, when the "Stress FPU" option is selected, the CPU temps spike to 94c despite being at stock clocks and 1.35v on a 360mm AIO. Not sure if it's meant to do that, but it's quite worrying.
Getting WHEA errros is windows 10 1903, the errors started the day I replaced my 1600x cpu with a 3600, no other changes.
ryzen 3600 cpu
asrock ab350m pro4 motherboard
rx 5700 gpu
94° is pretty high , try to disable auto oc so that the proc never get higher than 3.8Ghz (and then test again to see if it's a temperature related problem, but i think if it was a processor temperature problem the message would be different, but 94° is still high , mine never gets higher then 75-80° depending on ambiant temp, with a 2 fan radiator wc)
you can upgrade your radeon VII to 20.4.2 too , would eliminate a gpu driver related problem, as i think most stable radeon VII drivers I saw were 19.11.3 and 20.4.2
and check your rams too ... memtest , or at least try first to not use them at there maximum freq (no xmp , just default , maybe 2133 or less)
1) test rams
2) upgrade gpu driver
as you change hardware , processor , memory , motherboard etc , don't forget to reset bios to default , better , reset CMOS on motherboard,
it can be useful sometimes