I remember doing research on this and I came across a couple stories where the heatsinks over time came loose, fell into the fan and were thrown about the delicate circuitry, so I shied away from that and instead put a silent wings in the Kraken to cool the VRM and RAM and put it up as fast as I could stand it.
I did similar with my Kraken G12, but with an NF-A9. But as I understand it, that's just not enough for GDDR6 memory.
Note that I have an evga Super Black, I think I read that only certain versions of their card had multiple temp sensors on them and the Black wasn't one? But if it is the average then it sounds like you are onto something. But if it IS the average, then why after reapplying paste do the temps plummet, stay that way for a few weeks then start climbing again?
I keep forgetting that EVGA has something like that.
Thermal paste is just a bridge; it's primary role isn't cooling. It makes me SMH when I see people suggest others use top end, expensive, thermal paste when they're having high temperature problems.
If the paste is doing it's job correctly, then the heatsink/radiator/pump/fans can do theirs. When it is not, then the others can't either. There are 3 instances where the paste can't do it's job:
-Incorrect application. For example, the dot in the middle doesn't work as effectively on Ryzen 3000 because of the multiple dies around the sides of the actual cpu.
-Dries up, which can take a few years or more with known brands.
-Cooler not mounted correctly.
Now, why would it stay that way for a time, and then start climbing again?
Sounds like something is coming loose over time, and that's not the paste's fault...
By the way the evga Hybrids for the 30xx is a 240mm radiator, so going by the advice here it should be more than enough for a non overclocked card? Wondering if a 320mm with the Hydro Copper custom would be overkill then?
2080 Super Black Edition vbios:
https://www.techpowerup.com/vgabios/212660/evga-rtx2080super-8192-190701
Board power limit
Target: 250.0 W
Limit: 292.0 W
^Again, that's across the entire package, and the gpu core makes up the bulk of that. You also have to remember that the card will try to boost higher on it's own if the available headroom is present.
https://www.techpowerup.com/vgabios/191285/gigabyte-gtx1080ti-11264-170323-1
That's my 1080Ti.
The latest version of Gpu-Z shows power draw from the core, and I've seen it pull quite close to the 250w board power target... again, that's by itself, even with the small overclock I have on it.
Unlike gpu heatsinks and full cover water blocks that handle the entire package, the hybrid coolers isolate the gpu core from the rest.
The H55 can manage, but only if the core is allowed to throttle down. If whatever you're doing constantly has it sitting at high usage for extended periods of time... I think we've already covered that 120mm hybrids can't really handle 200w+ of heat...