If you have an ASUS ROG Maximus XI Extreme motherboard and you’re using the ROG DIMM_2 riser card for your M.2 SSDs, by default you won’t see them from the get-go. This is by default as ASUS allocates the PCIe lanes to the appropriate PCIe slot and you have an onboard M.2 anyway which is the main slot.
So you’re wondering where are you M.2 devices that are connected to the DIMM_2 card. Well they’re there just not being detected by default. So to correct this, you have to set a few options in the BIOS.
How to Enable M.2 on DIMM_2 on the MAXIMUS XI EXTREME
- First up, power on or restart your PC. During boot sequence press DEL to bring up the UEFI BIOS screen.
- Next, go the Advanced tab and Select Onboard Devices Configuration.
- Press enter and you’ll be presented with options for onboard devices on the board. Scroll a few items down and you will see CPU PCIE configuration mode.
- Here you can select what configuration you want. The DIMM_2 borrows PCI-e lanes from the 2nd x8 slot so you’re dropping lanes from the x16 GPU slot to these slots if you use them.
- You can choose to fully wire the 2nd PCIe X16 slot to the DIMM_2 riser which effective disables your second PCIe slot though I haven’t tested this to confirm (will update soon.)
Do note that when using a SATA M.2 device on the DIMM_2 slot, that disables the SATA port 2.
So to summarize: to enable M.2 on DIMM.2 on ASUS Maximus XI Extreme, all you have to do is enable it in the BIOS settings.
Yup, its that simple but enthusiasts tend to ignore the manual and specs page and dive right now. I know that feel, bro.