XMP Issues! ASUS Z790 Apex Encore | i9-14900KS | Corsair Dominator Titanium 8000mhz 2X24

[KaoticKarma]

So I am having issues enabling XMP and getting it stable beyond 6000mhz. I have been fighting this for months now. I have been through 2 apex boards, 4 different sets of ram from the QVL list, 2 i9-14900k's and now a i9-14900KS. I've tried everything I have been able to find on the forums with no luck. I've tried XMP 1 and XMP 2 and no difference. I have updated to the most recent Bios of 1503 as well. I researched the board before I started the build and this was the way to go for 8000mhz, but I cant seem to get it to work. I would be happy at this point to get to 7600mhz, but I cant get anywhere near that. I can pass memtest86 at 7600mhz but fail kahru in seconds. Usually by 7%

SP = 106
MC = 87

[Silent_Scone]

Same but not the same. IMC VDD, VCCSA and IVR (VDDQ TX) are all CPU dependant. Tuning these rails is the easiest method of tuning frequency.

[KaoticKarma]

yeah thats what ive been working on since last night. Going up in intervals of 0.05. At 7600mhz, no matter what I change, karhu starts erroring at 7%. And its not just 1 or 3. By the time it hits 25% its at 30-40 errors. Ive replaced boards, replaced memory, replaced cpus. I dont know what else to try. I dont understand how with this setup, I cant at least turn on XMP 1 set it to 7600 and be fine. Especially with the 14900KS. There has to be something, somewhere that im missing. I just dont know enough about RAM timings to dig into that portion of it. Ive built 30 PC's over the years and never ran into these issues. Though this is my first DDR5 build, but it shouldnt be this difficult. I feel like companies are selling on a promise of speeds that arent very realistic unless you have in-depth knowledge of timings and tuning on the DDR5 platform. 

I know you have a lot of experince with this, if this was your setup, what would be your next step?

[Silent_Scone]

What cooler are you using? Can you use my profile at 7200MT?

[KaoticKarma]

**EDIT** The corsair is on my streaming PC. I have the 360mm Asus Rog Strix LC II on this PC. I can get 7200 to 1500% on harhu before erroring

[Silent_Scone]

Wondering if you could benefit from a contact frame. What are the core temps like in Karhu?

[KaoticKarma]

I originally had a contact frame and went back to the ILM to see if that was the issue. Not sure how to check temps in Karhu

[KaoticKarma]

This made me start digging into fan and cooler settings. When running a full system stress test it shows overheating detected in AIDA. and says it is being throttled at 8%. Is 88c too high? I thought these chips were built to withstand much higher temps well over 100C. 

[KaoticKarma]

Been going through the article and testing voltages and such and still nothing. Im just baffled

[KaoticKarma]

So I can pass memtest at 7600, but error on kahru is the first 20 seconds. Im not even trying to hit 8000 at this point but have no idea why I cant even get to 7600

[AMD180]

Currently experiencing this exact issue with my second Apex Encore and 14900KS running with G.Skill 8400 Royal kit

I have another 14900KF with 790 Apex Encore & 8000 Trident G.Skill kit and it runs absolutely flawlessly at 8200MHz daily on XMP1 - no errors or issues at all. Literally just set XMP1 and up the frequency to 8200MHz and it runs like a dream. This second rig currently will not get close to it. 

The rig with the 14900KS is a total lemon at the moment and I cant boot over 6400mhz and it is running the 1503 BIOS, where as the second rig is not.

I should mention no contact frame on either setup.

I believe it is a BIOS / 0x129 micro code issue at this stage.

Did you try this on an older BIOS before updating to 1503?

I unfortunately updated the BIOS before setting the XMP.

I would advise anyone with a APEX ENCORE to not update to 1503, it appears to zap all overclocking potential.