[HKPolice]

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?

 

[MrTOOSHORT]

Up to 1.45v for 24/7

 

[Raghar]

Quote:

Originally Posted by HKPolice

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.

Skylake permitted max 1.35V. There are DDR3L, which are 1.35V type of DDR3. Anything else was forbidden. (Thought these DDR3L still defaulted to 1.5V JEDEC, 1.35V should be set by user or by XMP optimized for 22 nm CPUs. Translated USER should avoid XMP and set sane values by hand during first boot.)

When you are not running chiller or LN2, setting too high IMC voltage simply means CPU goes poof.

 

[HKPolice]

Quote:

Originally Posted by MrTOOSHORT

Up to 1.45v for 24/7

I've seen that figure thrown around but no hard evidence to support it. Intel has said that max is 1.5v http://www.legitreviews.com/what-is-the-safe-voltage-range-for-ddr4-memory-overclocking_150115, but this statement was during the Haswell era. Not sure if anything has changed now.