I looked through the Intel datasheet and it only lists VDDQ of 1.2v +5%. So that can't be the max recommended voltage since all kits these days are 1.35v stock, and 1.2v +5% is only 1.26v.
According to wiki, Coffee lake is the first CPU to completely ditch DDR3 support, both Skylake & Kaby Lake still had DDR3 support on the IMC.
Since DDR3 defaults at 1.5v, I would assume those older IMCs would be more robust against high voltage.
So the question remains: what is the max safe 24/7 DDR4 voltage for Coffee Lake?
According to wiki, Coffee lake is the first CPU to completely ditch DDR3 support, both Skylake & Kaby Lake still had DDR3 support on the IMC.
Since DDR3 defaults at 1.5v, I would assume those older IMCs would be more robust against high voltage.
So the question remains: what is the max safe 24/7 DDR4 voltage for Coffee Lake?