What is CSM and do I need it enabled?

[gupsterg]

That being said if I were installing Windows 10 on a 970Evo 500GB NVMe M.2 in a ROG Maximus X Formula, would I need to change CSM to disabled and then under secure boot chnage the OS type to "other type" and clear secure boot keys?

When you change the OS type to " Other Type" the secure boot keys will be "Unloaded" thus not apply.

You can installed Win 10 with CSM enabled or not.

[ukasyah_rz]

I cant speak directly from your board but on a similar buid 7700K and M9F I had to leave the CSM enabled to get it to boot from the USB. Dont remember having issues later setting to disabled. When windows wont boot on any issue like this whats worked for me is to go back a step, let windows boot, reboot to safe mode, then turn CSM off and save and exit. Then it willl boot in safe mode. restart...done

If u use Rufus for bootable, there is option for UEFI CSM or UEFI Non-CSM.

[emsir]

If I recall correctly, you must disable CSM before installing Windows 10. If you installed Windows 10 with it on, then it won't let you disable it.

Not true. You can disable CSM anytime you like, and enable it too.

[npapanik]

My config:
- Asus Prime X470-PRO with latest BIOS (5220)
- Asus ROG Strix RX VEGA56

My problem is that when I disable CSM support in the BIOS, I cannot get into BIOS again whatever I do, SHIFT+restart in Windows 10 or press DELETE or F2 at boot sequence. When I do these two actions my monitor (Dell SE2717H connected via HDMI) pops up a message that the resolution is not supported! So it seems that the system is in the BIOS screen but the output resolution is wrong...

Note that Windows are working perfectly OK, its just that I cannot get to BIOS. If I reset the CMOS I am able to get to BIOS again but CSM is Auto in the default BIOS settings.

I am the only one having this?

[jamith]

My config:
- Asus Prime X470-PRO with latest BIOS (5220)
- Asus ROG Strix RX VEGA56

My problem is that when I disable CSM support in the BIOS, I cannot get into BIOS again whatever I do, SHIFT+restart in Windows 10 or press DELETE or F2 at boot sequence. When I do these two actions my monitor (Dell SE2717H connected via HDMI) pops up a message that the resolution is not supported! So it seems that the system is in the BIOS screen but the output resolution is wrong...

Note that Windows are working perfectly OK, its just that I cannot get to BIOS. If I reset the CMOS I am able to get to BIOS again but CSM is Auto in the default BIOS settings.

I am the only one having this?

Asus ROG strix B350-F with BIOS 5220, I have the same situation, Im unable to get to the BIOS after disabling CSM.