ROG Maximus Hero Z790 + GSkill 6800 = XMP doesn't work

[rios0rios0]

Hi guys.

My configuration:
Intel i9 13900KS (brand new, I changed 2 months ago since the old one was with microcode side-effects, damaged physically)
Asus ROG Maximus Hero Z90 = BIOS Version 2602 (2024/09/27)
G.SKILL Trident Z5 RGB Series 64GB (2 x 32GB) 288-Pin DDR5 6800 (PC5 54400) F5-6800J3445G32GX2-TZ5RK

This combination never worked with XPM. There are several topics here in this forum about the same issue, with the same motherboard, but different GSkill models and speeds. And believe me, I tried already what they are saying. The BIOS doesn't even POST. The MB keeps in a infinity loop restarting after 5C, 7F red and then restarts.

Also, I tried all possible profiles: XMP I, XPM II, and XPM Tweaked, but none worked.
Interesting that I've being waiting and updating my BIOS regularly, and since I built this computer, it never worked the XPM. I'm running at DDR5-4000. Waste of money with this memory to run like this.

Can you guys help me understand please? Does Asus want me to regulate any special and tricky voltage to make this work, instead of just putting a simple bult-in profile?

Or is that GSkill which is the issue?

Cheers!

[Silent_Scone]

Hi @rios0rios0 

Have you tried anything else in terms of tuning? Some CPUs may struggle with that frequency and density on a 2 DIMM per channel board. 
Manually reduce the DRAM Frequency to 6000MT and above and see at which point the system POSTs successfully.

[rios0rios0]

Hi. Thanks for the answer.

The BIOS doesn't allow me to switch the frequency in some profiles. I'll need to create an XPM customized profile then?! And then, change the frequency to below 6800 which is the promised by GSkil... And I'm using the most High-end CPU... Why doesn't that just work? I need to "lower"?

I'll try that. But, probably, I'll end up in 4000Mhz again.

[Silent_Scone]

You can change DRAM Frequency manually after selecting profile. Use XMP II as this uses the default DIMM profile which will likely contain more relaxed memory sub-timings.

For more info on XMP see here.