i have r9 390x MSI and his temprature after i play 5 minutes or even less is crazy (after 5 minutes about 85-86) if i use KUMBOSTER stress test of MSI AFTERBURNER after 2 minutes i get about 90C.
also i have 2 more wierd things
1:the kumboster says that my graphics card is R9 290X instead of R9 390X
2: when i run a game at the moment i open it the temprature jumps from about 60 to about 70-73 in 1 second, and if i close the game or do ALT+TAB the temprature go down back to about 60 in one second
That isn't dangerous, and is pretty normal for a stock fan profile. You can use MSI Afterburner to create a custom fan speed curve to get it as low as you want.