Z450 - Pro 4x8G RAM not functioning
Z450 - Pro 4x8G RAM not functioning
Occasionally certain setups face problems with four sticks when XMP is active. It increases pressure on the memory controller, which may exceed its capacity. This can lead to a situation that isn't resolvable unless you return the RAM package and swap it for two 32GB units or turn off XMP in the BIOS settings.
Assuming you're using a 10th gen CPU on a Z490 board, the CPUs are not rated for DDR4-3200. The i7 and i9 parts are rated for DDR4-2933 and the i5 and i3 parts for DDR4-2666. Anything above that is considered overclocking and there's a chance that the memory controller on the CPU can't handle 4 sticks running above the rated speed. Usually, Intel does fine with high memory speeds and having all the slots populated, but sometimes the IMC isn't that great.
Have you bought two 16gig kits or one 32gig? That can sometimes be a problem, but as YoungBlade said you are not guaranteed that xmp is working.
Thank you for your response, but I noticed it's already disabled.