As always, Pook Is correct. There is a lot of Nuance to this topic. I told
to try to find the max of the chip at 1.45v because I know from experience the Chip can handle it, AS LONG AS you can keep it at around 85c or below during your load.
Voltage is NOT what kills chips. Current, and Heat, is what kills chips. If you know what you are doing, as
Eluded to, you can run the chip at 1.7v under extreme cooling and be completely fine. Under normal ambient conditions, you just want to avoid pumping enough current to overheat the chip, its literally that simple. With that particular chip, 85c tDie can be run at 100% CPU Load all day every day and never skip a beat. So what ever voltage you use (Because this will vary from individual chip to individual chip, and from cooling solution to cooling solution) just make sure that under full load you can keep the temps at or below 85c, and you have nothing to worry about. For transient loads is even ok to go above that, as nothing is absolute, just as a general rule of thumb for the 2nd Gen Ryzen CPU's, if you keep the chip at 85c or below under full load, you will never have a degradation issue.
Obviously, I should not say Never, the Chip has only been out for not even 2 years yet, but based on my experience with both Gen 1 and 2, I can confidently say that you will not have noticeable degradation for at least 3 years, and its probable that if you follow that guideline you probably won't have any degradation for years to come, unless it turns out that their is some flaw with the Zen Silicon, which is unlikely.
So to be on the super safe side, keep your chip at or below 85c, and you have no need to worry. You can honestly go above that and be completely fine for those who know what they are doing, but if you are unsure, follow that guideline and you can put your mind at ease.