The XMP profile has stopped functioning after months of use.
The XMP profile has stopped functioning after months of use.
I own a 9900k on a Z390 Gigabyte board. My 3200mhz DDR4 works well with its XMP setting for this board and the Z170 before that. But after unplugging the PC, it won’t boot with the XMP profile anymore—it only boots with manual OC up to 2600mhz, even if I boost the voltage. I’ve cleared CMOS, updated BIOS, and tested different RAM sticks. Should I swap the motherboard or CPU first? Is this a problem with the memory controller?
Consider testing a different 9900k chip first, then evaluate if a new motherboard is needed.
It would help if you told us what exact Z390 GB motherboard you have. There is a 90% chance your board switched to the backup BIOS and the backup BIOS is a different version than the main BIOS, which may be older and not compatible with your RAM. Did you ever update the BIOS before? Do you remember what version you updated? (you can just look where you downloaded it). Is the BIOS you currently boot to the same version as that? Switching Bioses on the Aorus master and Extreme is far different than on the lower tier boards. So please tell us what board you have.
Have you verified the BIOS version you're using now versus the one before? If it has changed to an older backup version, you might be able to upgrade back to the latest, though newer releases can have issues. Switching it back to the main BIOS can be tricky. Generally, it's suggested to enter BIOS, turn off the AC power switch (or unplug it) while in BIOS, hold the reset and case power buttons, and keep them pressed until the system restarts. This process often resets the BIOS settings.