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.
I disabled PBO and used HW info 64 to examine additional sensors. The CPU has three temperature sensors of which one is a bit (about 5 C at max T) higher than the others and also sees these spikes in temperature. The two others do not see these spikes.
Disabling PBO also reduced the temperature when rendering considerably from (based on eye fitting) 105 +/- 5 to around 75 +/- 5. I have not checked the power draw. Without PBO the cores are clocking up to 4175 to 4350 MHz depending on core. The minimum clock is still far too high at 3300 MHz (except core 5 which dropped to 2900 MHz at one point).
I have not tested if there is actually a difference in performance with and without PBO.
Ryzen or Windows balanced power plan?
The Ryzen CPU's don't seem to be worth overclocking without water cooling.
If they are cool enough they boost great anyway.
Load up Ryzen master and hit the reset button to make sure something in the bios isn't keeping your CPU from downclocking and sleeping cores.
I tried everything on a 3600x, theres no reason to use pbo or autooc, diable pbo in bios, set both cppc settings to e nable also in bios and do a manual OC, your temps will lower around 20º and better performance
If you are going to push your CPU that hard, get a tube of Arctic MX-4 and a dual fan water cooler that fits the top of your rig
remove the vendors thermal material, put a very small dab of MX-4 on, attach the pump. Hook up the power and LED FX etc.
The power up for a while and power off at night, this will cause the MX-4 to spread better over time.
The you can run Blender 24/7 and not fret about a LN cooler being next up