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DDR5 Memory won't go past 4000mhz to reach 4800mhz on Z690-F

Kravena
Level 7
Just put together a Z690-F (Bios 0702), 12900k and 4 x 8gb Crucial ( CT2K8G48C40U5 ).

Memory isn't listed on the QVL, just to get that out of the way.

It all works, but if I set the MB to XMP I to enable 4800mhz, the motherboard will not post. When it does eventually boot, the memory drops to 4000mhz and not the 4800mhz on the XMP I.

Anyone else getting similar issues ?
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j_elterman wrote:
After trying just about everything else, I got my memory to read at 4800mhz by installing the latest bios, moving the RAM to two different slots (still with a slot between them), and setting the BIOS to XMP2.

If you haven't already tried swapping the RAM slots, might be worth a try. I really appreciate this thread and Shamino for posting the updated BIOS. Thanks for helping me solve this.


Yup that did it for me thanks. Mine now work in channel B, using the XML settings. I have Corsair Dominator DDR5 5200Mhz, which is on the QVL list. It would be interesting to know why they only work in channel B. It recommends in the guide you get with the motherboard to use channel A, not too sure if that actually makes much difference. Hopefully there'll be another BIOS that addresses this.

The 1.25v suggestion was a good one (and I tried it) but unfortunately it didn't work.

I'm going to have to try channel B with the ram sticks. That's quite interesting and would be surprising to see work! If so, I wonder what the underlying issue would be (why would that happen).

Defective board?

Perhaps the other channel is acting differently in some way?

Thanks for sharing!

tawzzer wrote:
It would be interesting to know why they only work in channel B. It recommends in the guide you get with the motherboard to use channel A, not too sure if that actually makes much difference. Hopefully there'll be another BIOS that addresses this.


Many Strix Z690-F owner have the same problem. It's still unknown what is the reason. In my case, I initially thought the RAM is to blame. After getting a new 2 x 16 GB kit, the same situation: Only the B channels were working. Then the vendor changed the board. At the replaced board, A and B channels were working. I doubt this is a BIOS matter. The issue is known since November 2021, and we got already several BIOS updates since then. I fear it is an issue related to the circuitry of some Z690 Strix boards.

My RAM supplier suggested it might be a power issue but as they aren't the vendor for the Mobo, I am taking that with a piece of salt. It does suggest I wont be easily able to run 4 sticks anytime soon. Even the RAM supplier has suggest only 2 sticks are recommended since you cannot get packs of 4 that are matched.
I am still relieved that I am reaching 2x16 5600MHz with non QVL approved RAM.

I got a new Z690-E the other day and memory wouldn't work in A1 or A2, only B1 and B2. Tried both a Corsair pair and Kingston. I set up a replacement with Amazon and got a new one today and all 4 slots are working. I have Corsair 5200 in slots A1 and B1 and Kingston 5200 in A2 and B2 and the machine posts. Running memtest now. When I booted they were running at 4000MHZ. I turned on XMP 1 and now it is at 5200MHZ.

birdjungle wrote:
I got a new Z690-E the other day and memory wouldn't work in A1 or A2, only B1 and B2. Tried both a Corsair pair and Kingston. I set up a replacement with Amazon and got a new one today and all 4 slots are working.


Exactly the same happened in my case. A1 and A2 would not work, only B1 and B2. Vendor changed the board, and then it worked. I have seen many similar reports about Z690 STRIX boards. It's like a lottery. I think we have to assume that there is a hardware /design issue.

Switching to A2/B2 worked for me.

ASUS B660M-PLUS WIFI using Crucial CT8G48C40U5 8GBx2 (4800MHZ)

Stuck at 4000MHZ on A1/B1, would not post using XMP I or XMP II.

I noticed RAM running @ 4000MHZ only because I was looking to upgrade and checked BIOS to play with RAM settings before I do.

I guess I won't be running 4 sitcks.

Silent_Scone
Super Moderator
If people are using Channel B1 and B2 for 2x DIMM configuration then you're only using a 64 bit wide channel (dual and not quad), which is easier on the IMC and memory.

Use A2 and B2 as per the manual.
13900KS / 8000 CAS36 / ROG APEX Z790 / ROG TUF RTX 4090

please delete here - opened a new thread

It worked! Switching the ram from A1/B1 to the A2/B2 channel fixed everything.

In A1/B1, I couldn't boot past 4400mhz (and even then, it crashed so I was running it at 4000mhz).

When in A2/B2, I was able to boot at 4800mhz with XMP2. From there, I figured I try 5200mhz and that worked too! So today I just went from 4000mhz -> 5200mhz by switching the slots.