The original post: /r/overclocking by /u/jgpstuart on 2025-01-24 01:13:20.
I’m documenting this here for anyone in the future who attempts a build like this. I found one reddit post that allowed me to get this stable but that post is now archived, so I can’t add comments to it. The original post I refer to is found here: STABLE 128GB(4x32GB) DDR5-6000 CL30 on AGESA 1.0.0.7b : r/Amd
Specs:
- Processor: AMD Ryzen 9 7950X3D, air cooled
- Motherboard: MSI X670E Tomahawk Wifi
- Memory: 4x 32GB Corsair Vengeance DDR5 RAM 128GB 5600MHz CL40 - CMK128GX5M4B5600C40
I chose this build not knowing about the limitations of the AM5 integrated memory controller (IMC), the issues with dual-channel 4 DIMM with DDR5 memory, and qualified vendor list (QVL) list for this MSI MOBO, but have learned a lot since trying this build. The main limitation is that the system will default to 3600MHz for the memory (despite the rating of 5600MHz). It would not post when I enabled XMP and with XMP disabled I tried manually stepping it up 200MHz at a time and could get it to almost 5000MHz but never consistently past that. I tried the “Memory Try It!” presets that came with the motherboard and it would post with one of them, but was failing memtest86 (specifically test 8).
Before I gave up I tried manually setting the voltages and frequencies using the values in the post linked above from u/andymetzen. That post is for a different MOBO/RAM combination, but I figured I would try it. I used everything in those settings except I set it to 5600MHz instead of the 6000MHz used there. To my utter surprise it has posted just find and passed 13 hours of memtest86 and 2 hours of y-cruncher tests.
I have not had any crashes, BSOD, or issues booting with these settings. I’m adding them here to help anyone else who might contemplate 128GB builds with AM5. While this is passing all the tests I’ve put it through, I’ve read a lot of people say that it still might not be stable when gaming or multitasking. I also have very little knowledge of overclocking and am nervous about just “yeeting” a bunch of values I found online into my machine without fully understanding what I’m doing! I’ve decided not to risk possible future instability and am switching to a 2x48GB 6400MHz CL32 build for both the speed increase and peace of mind (the new memory is on the QVL list).
Again, hope this helps someone out there. A big thanks to u/andymetzen for his great post documenting this in the first place!
