i had a crash at -170 mV an hour ago, yesterday everything was fine, so i just put another +5 mv , and i'll keep testing and seeing if my cpu is stable. And yes this undervolt improved a lot my temps , from going to 90 celsius under load , to 70 in package , and in idle from 50 to 30, it's a lot of improvement. (maybe because of the aio and the fans ) Also today , atm we have an outside temp of 31, and its expected to rise to 35 in 3 hours.
anyway, thanks man for your advice, and i'll just keep and eye if the pc crashes again,to rise the voltage in increments of 5 or 10 mv.