System fails to start with XMP settings.
System fails to start with XMP settings.
You observed changes in your PC's behavior today. It seems to be running normally yesterday but not now, failing to boot with XMP enabled. When it does boot, it reports XMP is active but the BIOS RAM speed is set to 2667MHz. Consider checking for updates, hardware issues, or driver conflicts.
That should be the highest rated non-XMP (JDOC) memory speed your CPU can handle. Share your build and we'll check it out.
When this applies, relocate the RAM. The manual states for models with 2 units, they fit into slots A2 and B2. https://download.asrock.com/Manual/B450M Pro4-F.pdf