STILL Unidentified Asus Z790-E XMP Problem

[mroth21]

After reading through a lot of threads, the real XMP problem with this motherboard has not been identified. I recently purchased a Z 790-E with an Intel 13900K processor and Corsair DRAM on the QVL. However, my system only boots with XMP disabled, and the BIOS (UEFI) shows that the RAM is only running at 4000 instead of the expected 4800. Interestingly, this CPU and DRAM combination worked perfectly on an Asus Z 690-E motherboard using XMP 1 profile at 6600. The only difference between the two builds is the inclusion of an Asus TUF 4080 GPU. Has anyone else out there experienced this problem? Does anyone have a solution?

I'm not a NOOB and have building gaming rigs for many years. I have never encountered a problem like this. Normally, I'd suspect a bad motherboard or bad RAM, but too many builders out there are experiencing similar problems with the Asus motherboards supporting XMP.
My system specs follow:
Asus TUF Gaming RTX 4080 OC
Asus  Z 790-E Gaming Motherboard
Corsair Platinum (on qvl) 6600 DDR5 DRAM
Corsair AIO cooling
Corsair 1000-watt power supply
Corsair D5000 with many fans

If anyone has any suggestions, please let me know. At this point I think I've tried everything and suspect crappy BIOS development.

[Jiaszzz_ROG]

Hello, @mroth21 

May I ask if you only enable it when XMP is disabled? Are you referring to XMP I or XMP II?
If you enable XMP, does it result in a blue screen, failure to boot, or any other issues?
What your current BIOS version is? Have you updated it to the corresponding Intel ME version?
Have you tried clearing the CMOS to troubleshoot the issue?

Thank you.

[mroth21]

I take every bad thing I said about Asus motherboards.  I finally solved the problem and I'm embarrassed to say how.  However, it's only fair that I tell all about what magic thing I did to solve my issue... I read the manual.  I had two sticks of RAM, DDR5 6600 and yes, I put them in the wrong slot. I should have known better; I've been building systems for quite some time. On my board, it will not post using XMP I or II if the RAM is in the first and third slots. I was able to run the RAM at the advertised 6600 once I moved them to the 2nd and 4th slots just. like the picture in the manual.  So with all that said, Asus, I apologize for criticizing your BIOS development. I was at fault.

I've since populated all slots with DDR5 7200 and although it's a bit unstable on XMP I, I dropped the speed to 7000 and switched to XMP II. The system has been rock solid ever since, and I'm happy. Thanks, Jiaszzz_ROG for taking the time to check in with me.

On a side note, the QR?? code on the motherboard bounces between 34 and 35. Is this normal? On my Z690 board, it stayed at AO after boot.

[mroth21]

What I meant to say is,  "I take every bad thing I said about Asus motherboards back"

[Jiaszzz_ROG]

Hello, @mroth21 

We appreciate you reviewing the pertinent documentation to further investigate the problem.
The Q-Code 34 represents memory initialization, the Q-Code 35 represents CPU initialization during the POST process, and the A0 indicates that "IDE initialization is started."
This indicates that the motherboard is initializing integrated drive electronics devices, which are hard disk drives, during a phase of system boot-up to ensure they are correctly recognized and prepared for use.
If there are no abnormalities during system operation after boot-up, it is recommended to continue monitoring during usage.
Please also refer to the Q-Code list at the end of the ROG STRIX Z790-E GAMING WIFI user manual to confirm the displayed code and its corresponding result, or refer to [Motherboard] Common Q-CODE(Error CODE) and Troubleshooting if needed.

Thank you.