M.2 Not Showing Up ASUS Prime Z390 [SOLVED]

If you’re using an ASUS Prime Z390 motherboard and your M.2 drive isn’t showing up in the BIOS  or in Windows, don’t worry – you’re not alone.

A number of users have been reporting this issue, and we’ve put together a guide to help you fix it.

In this article, we’ll show you how to troubleshoot the problem and get your M.2 drive up and running again.

It is not as complex as installing Asuswrt-Merlin, but we’ll also go over some of the most common causes of this issue and provide some solutions.

Why Your M.2 Is Not Showing Up On Your ASUS Motherboard

Some ASUS motherboard supports up to five M.2 drives which is really impressive especially if the motherboards are mainstream.

Although ASUS motherboard doesn’t really comes with issues, the only challenge that you might be facing is with you M.2 slots.

The reason for this is that, not all of the M.2 slots are enabled by default, so chances are you may not find any of your M.2 drives in your BIOS .

Don’t consider your drives os slots broken just because your M.2 are missing. They are only disabled by default and need to be enabled through your ASUS BIOS utility.

You may also be asking yourself:

Why Is My M.2 SSD Not Showing Up In The BIOS?

The main issue is that the bottom two M.2 Drives on the board actually share their PCI Express  lanes with the actual PCI Express  slots on the motherboard. So, basically you have to go into the BIOS  and enable those two bottom slots.

How To Enable M.2 From ASUS BIOS

The first thing you want to do is to access your BIOS  before you can begin tweaking your BIOS  settings.

Accessing ASUS BIOS :

What you want to do is keep on hitting the delete key on your keyboard repeatedly and you’ll be dropped into the BIOS . Make sure it’s not the backspace you are hitting but the delete key.

Switch from easy mode to advanced mode:

If you are using an extreme board, you should be dropped into the advanced mode. But if you’re not for some reason, you can hit f7 to switch to the advanced mode from easy mode.

Most ASUS motherboard may cause you to drop into easy mode but if you hit f7, you will be taken to the advanced mode.

From advanced mode you want to go over to the advanced tab and then click on onboard devices configuration.

Scroll down to cpu pcie configuration mode. By default, it’s set to PCIEX16_1 + PCIEX16_2 which enables both PCI Express  slots on your board.

To enable our two bottom M.2 drives we have two options.

These are the options:

  • PCIEX16_1 + PCIEX16_2 + M.23
  • PCIEX16_1 + M.2.2 + M.2_3

PCIEX16_1 + PCIEX16_2 + M.23: This is going to enable the most bottom M.2. drive or M.2 slot on the board and then it’s going to cut the lanes on the second PCI Express  slot in half. So, you’re going to go from eight lanes down to four lanes to enable just the bottom slot now.

if you want to enable all of the M.2 drives or the bottom two M.2 slots on the motherboard, you should select the PCIEX16_1 + M.2.2 + M.2_3

PCIEX16_1 + M.2.2 + M.2_3: This is going to fully disable your second PCI Express  slot, but it will fully enable the bottom M.2 slot. So, if you wanted to fully load this motherboard up with drives, that’s what you would go ahead and do.

Make sure you hit f10 to save and the click on ok.

By just enabling those bottom two M.2 slots, you should be able to notice your M.2 drives or slot showing.

How To Enable NVME M.2 In BIOS ASUS

To enable NVME M.2 in your ASUS BIOS, this is what you must do:

While you are still in your BIOS on the advanced tab, scroll down to the M.2 PCIe mode and make sure it is set to enabled.

Some other ASUS motherboards might require you select the dropdown which is next to PCI Express X4_3 Slot Bandwidth and change it to M.2 Mode.

It really depends on the ASUS motherboard you can know which method will be more applicable to you.


Now you can rejoice. If you followed my instructions correctly, your M.2 drive compatibility issue should have been resolved. This means that your M.2 drive should now be visible in the BIOS and ready to use.

Now you can go ahead to insert your M.2 SSD drive into its slot knowing that your drive will be found since you have enabled M.2 through the BIOS utility tool.

If you have any questions, make sure you contact us because we happy to hear your complaints and help you resolve your problem at no cost.

Support me by sharing!

Solomon Omolabi is a seasoned IT professional with 10 years of industry expertise. As the owner of bestsoltips.com, he provides meticulously researched and comprehensive articles that effortlessly tackle any technical challenge. Solomon's contributions have earned him recognition on esteemed professional platforms, making him a trusted authority in resolving complex IT issues. Read more.

Leave a Reply

Your email address will not be published. Required fields are marked *