Z890 265k paired with CUDIMM 8400 shows instability in XMP mode.
Z890 265k paired with CUDIMM 8400 shows instability in XMP mode.
Hey everyone, I just finished putting together a new PC setup. It includes an ASUS ROG Maximus Z890 Hero with an Intel Core Ultra 7 265K processor, a G.Skill Trident Z5 CK 48GB (two 24GB modules), and a 288-pin CUDIMM DDR5 8400 (model F5-8400C4052G24GX2-TZ5CRK). I verified that both ASUS and G.Skill confirm compatibility with my motherboard and memory kit.
After assembly, I updated the BIOS, chipset, IME, and other settings. Right now, I’m running the latest BIOS version (1603). Immediately after, I encountered crashes during gameplay—Monster Hunter Wilds, Elder Scrolls Online, and Marvel Rivals. Both CTD errors and full system freezes appeared.
I ran Memtest shortly and got similar results. Then I reset the BIOS to defaults and tried again with a clean slate using 6400 CL50 speeds for four passes. This time, Monster Hunter Wilds ran smoothly for an hour without issues.
My thought is that these new CUDIMMs are still being fine-tuned. I recall similar problems when DDR5 first launched on my 13900k system; after a few updates to BIOS/microcode, everything stabilized and XMP worked well. However, since this build isn’t super recent, I’m unsure if manual tweaks (timing, voltage, clock) are necessary.
Anyone have experience with this setup? Let me know your thoughts!
These speeds are quite extreme. If you truly need them to operate at maximum velocity (even if it might not show obvious improvements), you’d likely need to return the product. Otherwise, setting it to the optimal speed—around 6000 CL 30—should suffice.
It seems like you're planning a gradual approach, likely reducing your target by 200 each time. Your current performance on a 13900k is 7200, which isn't a massive jump from what you did before.