Stress test (AVX) 92c was about the hottest youd want to let it get.
Normal full load usage id want to be no higher then low 80s.
But thats just where I personally feel safe to take mine and im running a custom water loop.
You can read else where that it should be safe up to 90c for prolonged use and burst up to 100c with out doing damage or significantly reducing its life.
Over 1.3v is "safe" but there is more to it than just voltage, cooling and typical load play a huge role. Up to 87c sounds really high for a 6 core chip with basically stock voltage though.
What cooler do you have? What do you use the computer for? And what are you running when temps get that high?
In the mid 80s is safe during a stress test but I'd expect it to degrade faster if that's happening during gaming or even encoding if you depend on that for work. It could be safe if you run it at 90c 24/7 for all we know, every CPU is different but if it were mine I wouldn't let it get that hot regularly.
Oh I didn't realize you had an AIO. Those temps are probably normal for that cooler but still what I'd personally expect out of an overclocked CPU.
Considering everything you've mentioned I'd say everything is running normally and is perfectly safe. Temps are higher than I would want on my rig but if you aren't overclocking you don't need the thermal headroom as much, if you start going over your current temps in games you might want to start investigating the paste, mount and the CLC its self.
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