No, none of your RAM is operating at the claimed speeds.
No, none of your RAM is operating at the claimed speeds.
They also support 1.52V in the VID table. I don’t care about the safe voltage suggested by Intel. I’m aware of people using over 1.6V memory voltage with DDR4 on Skylake and later without issues over time, so this isn’t a concern. For the OP’s DDR4 system, regarding 1.5V DDR3 on Skylake, I’m not sure. It might be related to on-chip termination or improper resistor settings.
You're focusing on stability and durability. If your RAM isn't reliable, boosting the voltage might be necessary. Your initial comment suggested it wasn't safe, but it doesn't address the risk involved. Intel's specifications can be exceeded during overclocking, which is why caution is important. We're only talking about memory overclocking here.
It’s obvious that A. OP missed the silicone draw on the IMC and received a chip that only delivers what intel said (2666MHz) or... B. the DDR4 modules are faulty and RMAd would be the better option here, which means running a memtest86 on both to check for issues... C. Motherboard compatibility problems? That’s frustrating but possible...