Question PC won't POST if RAM is set to its advertised clock speed

[kinpatsu]

After upgrading my system last week, I've been running into several issues, one of them being RAM speeds. No matter how hard I try and how much time I spend changing settings, my system will straight away refuse to boot when trying to run my kit over 3000MHz. I've tested two different pairs (both sit in the slots described by the motherboard, A2 and B2), and both have the same exact problem, only thing that I can change is the timings. Running XMP and let it setup everything automatically leads to the system not POSTing, and so does setting everything manually

The two sets of RAM are:
First: Corsair Vengeance 32GB (2 x 16GB) DDR4 CMK32GX4M2Z3600C18 (not QVL)
Second: T-Force VulcanZ 32GN (2x16) DDR4 3200 TLZGD432G3200HC16CDC01 (QVL)

As for the rest of the system:
CPU: 12700kf
GPU: GTX 1070
Motherboard: MSI Pro Z690-A DDR4 Wi-Fi (updated to latest beta bios)

Any suggestion would be much appreciated

 

[MeanMachine41]

Your kit of Corsair Vengeance 32GB CMK32GX4M2Z3600C18 are most likely not going to work due to the limitations of the IMC that supports up to 3200Mhz.
They may work with tweaking the Bios however no guaranty you will reach the rated frequency. Even then they may boot but not have stability and the fact that they have not been tested compounds the issue.
If you lack Overclocking experience, save yourself the frustration and return the kit.

T-Force Vulcan TLZGD432G3200HC16CDC01 are your best bet that are QVL listed.
First ensure your Bios and chipset are up to date (I personally don't use Beta updates) and test with just one DIMM in the DIMM slot meant for single channel mode. If OK then add the other Dimm using slots A2 and B2.
Go into Bios and set your XMP profile (If you have one). CPU can tell you the SPD.
If no XMP then set Timings to 16-18-18-38 at 1.4V.

Should the Overclock still fail then run a Memtest86 for 4 passes. (to eliminate the possibility of RAM errors). There are a few more tweaks you can try if unstable.

1. Try with a command rate of 2t
2. Loosen Timings one point.
3. Use the Dram calculator.

 

[kinpatsu]

Your kit of Corsair Vengeance 32GB CMK32GX4M2Z3600C18 are most likely not going to work due to the limitations of the IMC that supports up to 3200Mhz.
They may work with tweaking the Bios however no guaranty you will reach the rated frequency. Even then they may boot but not have stability and the fact that they have not been tested compounds the issue.
If you lack Overclocking experience, save yourself the frustration and return the kit.

T-Force Vulcan TLZGD432G3200HC16CDC01 are your best bet that are QVL listed.
First ensure your Bios and chipset are up to date (I personally don't use Beta updates) and test with just one DIMM in the DIMM slot meant for single channel mode. If OK then add the other Dimm using slots A2 and B2.
Go into Bios and set your XMP profile (If you have one). CPU can tell you the SPD.
If no XMP then set Timings to 16-18-18-38 at 1.4V.

Should the Overclock still fail then run a Memtest86 for 4 passes. (to eliminate the possibility of RAM errors). There are a few more tweaks you can try if unstable.

1. Try with a command rate of 2t
2. Loosen Timings one point.
3. Use the Dram calculator.

Getting back to you only now, I ran a memtest on both the kits and both passed with no errors.

While it's true that the 12700kf is certified to be working with kits up to 3200Mhz, I'm fairly sure that I've read around about people using 3600 and more kits without that many issues, so I'm not sure.

XMP, as I said in the post, straight up refuses to work. I've tried setting frequency and timings manually to match their profiles, but nope, the system just refuses to POST unless setting the voltage to ridiculous high amounts, which in turn made the system crash almost immediately after POST

Command rate is already at 2t and the issue happens at default timings as long as the frequency is over 3000Mhz.

I of course did all the tests with different BIOS updates too, and nothing really changed it

 

[jostegogar]

I've the same corsair kit, and i had to increase the dram voltage to 1.37 to get it work at 3600mhz, my cpu is i5 8400