So, if it is running 75 °C, no need to worry, right? Manufacturers of these cards claim that high endurance on high temperatures, but I guess they didn't analyse it in BTC mining with loaded all the time. You know some games are running above 80 °C all the time, but this loading may slow time to time. Should we mimic the same procedure to slow-down our mining rigs sometime in mining process or should we stay same loading all the time?
If all your GPU sensors are at 80oC or below, I wouldn't worry about it (or 85oC, for that matter)
the problem is, a lot of the time you'll run into a crap thermal paste job and while it may say 80oC on the main sensor, one of the others is at 95oC, etc..
Most of my cards run at below 70oC, but I do have a couple that I ran at around 80oC last summer, shrug...