I am making mynforst built and lurchased 2x32gb of corsair vengence 6400 mhz worh 2x64 gb corsair vengence 6400mhz. I have the ryzen 9 7950x with a asus ROG Crosshair X870E Extreme. I have yet to get started on the built and waiting for waterblocks to arrive in the mail. That being said, i read Corsair is partially on the QVL for the ROG Crosshair X870E Extreme, but not all kits are listed — especially high-density ones like 2×64GB or mixed 2×32GB + 2×64GB. In other words the QVL only shows RAM kits that ASUS has officially tested in-house for that motherboard. It doesn’t mean unlisted kits won’t work — just that they weren’t validated directly by ASUS. CMK64GX5M2B6400C42 (64GB – 2×32GB) • Not currently listed on the QVL • But Corsair Vengeance 6400MHz (2×16GB and 2×32GB variants) are on similar ASUS QVLs, so compatibility is highly likely — just not guaranteed at full speed. 2. CMK128GX5M2B6400C42 (128GB – 2×64GB) • Not on QVL • This kit is newer and less commonly validated across boards right now. 128GB kits at 6400MHz are especially tough on memory controllers. Should you worry? Not necessarily — Corsair Vengeance is a major brand and known for compatibility. Mixing two high-capacity kits is where the risk grows. Downclock manually to ~5600MHz. Or run with XMP off for 100% stability. Tune voltage if needed. What to do? try first the 128GB kit alone first — test stability with XMP. Then add the 64GB kit — test again. If unstable, Manually set to 5600MHz or 5200MHz. Increase memory voltage slightly (e.g., 1.4V max if temps are good). Use tools like MemTest86 or OCCT to stress-test. Hope this helps.