Hi, I just installed an AMD R7 3700X with stock cooler and PBO enabled.
Motherboard: MSI b450-A Pro Max.
Air flow should be fine.
When I use a 3D renderer like Blender I will quickly get temperatures at around 95 C and I have peaks to around 110 C.
My idle temperature is probably around 50 C, but the temperature graph consists of these weird spikes of sudden heat increase followed by slow dissipation, as shown in the screenshot before load.
In addition I also have a problem that Afterburner and taskmanager shows the CPU at 4200 MHz permanently. I'm in balanced power plan which solved that issue on the previous CPU, though I did reinstall Windows when installing the new CPU.
Afterburner claims that my CPU is getting around 140 W under load.