Just built Z790 Carbon WIFI w/13900KF, XMP Fails on 4x32 5600: here’s a temp fix

[PaulieDC]

I bought 128GB (4x32GB) G.Skill Trident Z5 DDR5-5600 for my C-WiFi and XMP fails. I’m on the .120 BIOS from 11/15/22. I get the orange light on the motherboard when I turn on XMP and it reboots and tells me overclocking the ram crashed, etc etc… then the stock 4000 is put back of course, and the BIOS comes back up. Of course this will need to be fixed in a later bios version, but for now I turned on XMP again, but then set DRAM to 5200 (G2 in the DropDown List) and it worked. I’m only going to bios now, I have not yet installed windows 11 pro or anything else and I may have to lower it some more if I hit issues but for right now if you’re running four sticks of 5600, 5200 should at least help you post.

FWIW I’m doing orchestration and film scoring and sometimes even 128GB ram isn’t enough, lol. But that’s why I have that much If curious.

 

[citay]

Yes, i've posted about it before. Often times, with four DDR5 modules, you will have to manually set a lower-than-XMP DRAM Frequency to make it work.

Four modules don't run very well with DDR5. The first sign is that there are hardly any four-module RAM kits available for DDR5 at all, and that's for a reason. Because once you use four modules, the maximum frequency that the memory system can reach drops down considerably. With four dual-rank 32 GB modules such like yours, you have the most stress on the memory system, and something about DDR5 really doesn't like this configuration. With DDR5 it's always better to use two modules only (and even with DDR4 that is advised, but four modules can at least work quite decently there).

I explain this in a bit more detail in my RAM thread under 2).

This all means that DDR4 is actually better for high-capacity memory configurations, because:
- It doesn't experience such a large drop in the electrical properties of the memory system when using four modules
- Four-module high-capacity kits are readily available (and at a lower price)
- Four-module kits are actually certified on the memory QVL at MSI
- They will most likely outperform their DDR5 equivalent due to DDR4's lower latencies, when compared to DDR5's necessary low required frequencies at this configuration.
This is because the overall higher DDR5 latencies can't be compensated for by higher RAM frequencies anymore, because using four DDR5 modules requires lower frequencies to be stable. Here's an article about RAM performance scaling, https://www.techpowerup.com/review/ddr5-memory-performance-scaling/

So, the MSI specification is not to be taken lightly. Even looking at two modules only, DDR5-6200/6400 kits are really causing some problems on Z690 boards with four RAM slots. That's on the upper end of what the signal quality currently allows for on Z690 with DDR5, unless you pump in ungodly amounts of voltage or use other tricks that are not the best for a daily system. Watch this spot in the video here where a RAM overclocker talks about that issue. DDR5-6400 and higher might only work properly on Z690 boards with two RAM slots, because the signal quality is better there than a four-slot board with two empty slots. And it also depends on the CPU's IMC (memory controller). So it's best to stay a bit more conservative, like DDR5-5600 for example... but: With four modules, you cannot dream to get anywhere near such RAM frequencies, you are lucky when it runs stable at a lower frequency!

With Z790 and the 13th gen IMC, they have improved the situation a little.
But a big drop in attainable frequency with four modules is still present, only at a slightly higher overall level.