Hello, I have a Ryzen 1500x that I'm trying to overclock on a Asrock AB350 Pro4. I was wondering if it was ok to have a high idle voltage of 1.3875 V, but drops down to 1.35 V under full load because of VDroop. The reason why I have it set like this is because this motherboard has no LLC, so I can only up the voltage to compensate for it.
Lower-binned Zen1 parts typically needed a lot more voltage to stay stable above 3.7-3.8Ghz. Keep temperature below70C and voltage below 1.425V and you'll be safe. At 1.38V temps up to 90C should be OK.
How are you measuring voltage, though? Motherboard sensors are probably not accurate; use HWInfo64 and look for the SVI2 TFN VCore reading. That's the internal voltage reported by the CPU in telemetry. It will vary closely with processing load as it's the result of Vdroop.
Higher temp and higher voltage always degrades a semiconductor faster so of course it will; but you are overclocking and that comes with the territory.
The real question is how fast and nobody can tell you that since it depends entirely on your silicon and how you use it. If running it 24/7 at 1.38/90C doing BOINC it might last 10 years before it starts going crashy or it might last only 1 year. But when it does, you lower clocks and voltage a bit and continue. And if it only sees that kind of extreme an hour or so a day total it could also last a full 30 years...or at least well beyond it's time to be even remotely relevant as a processing device. That's why it's 'safe' as it still outlives it's usefulness which is all that can be expected of any good overclock.