To start off, here are my specs:
Ryzen 3900X CPU
32 GB DD4 RAM at 3600 mhz
750W Gold+ PSU
2560x1440 display
Windows 10, up-to-date build
An air-cooled case with plenty of air circulation.
So, if I play at default GPU settings at 4k, my temps usually go up to 85 degrees at max. So, I am inclined to rule out having one of the faulty cards that instantly soar toward a 110-degree junction temp.
But if I manually tune my settings, I have realized that any max GPU frequency above 2400 mhz, or rather any frequency that comes with a power draw above 350W instantly sends my junction temps through the roof. I see a steady increase toward 90-100 degrees. To be honest, I have never stayed any longer to see where it would stop.
Some of you will say "Well, don't play around with overclocking" and you'd be right to say so. Then again, I have seen people overclocking comfortably to 3000 mhz and even higher with far lower voltages (people can go as low as 1020, whereas I cannot go any lower than 1125 mv).
I am torn in two here. On one hand, I am suspecting that I still might have one of the bad cards. On the other hand, I have a hunch that this is all caused by my PSU. It's not really an informed thought. I am merely pondering if a better quality PSU with higher capacity could make any difference. It's a stretch, but I am also wondering if a CPU upgrade could also possibly change things. Just a thought. Most probably it's not that.
Any thoughts? I'd really appreciate input from those who have tinkered around with undervolt/overclock on a reference model.