Asus z790 hero new build only recognizing 2 out 4 SSD drives

[Giode]

Hello, 

I have read and tried to research this issue as much as I can, and have not found a workable solution. I have four SSD drives installed on M2.1, M2.2, M2.3, and M2.4, and the bios and Windows 11 only sees two of them. I am not super technical, but doing the best I can to figure out why the other two $300 SSD cards are not showing up? 

My specs are:
Asus z790 Dar Hero
Intel Core i9-13900K
ASUS ROG Strix GeForce RTX 4090
Samsung 990 Pro SSD 4TB PCIe 4.0 M.2 2280
CORSAIR Dominator Titanium RGB DDR5 RAM 96GB

Anyone else who has had this issue and found a fix? Kind of at wit's end here. Thanks.

[MrAgapiGC]

Rules.

1. M2_1 share bandwidth with the first pcie express. When add it gpu will run in 8x. and the second pcie express will be disable. 

2. There is no other bfication on that unit aside that. 

3. remember to have the last bios in... 1704 and follow the guide on the ami screen. enter bios as it say f5 then f10 then get back to bios to make any changes like xmp!

Question they are empty? or have data? You move from another build? let check one by one. and let see i can help on this way

[Giode]

Thanks for the reply. So you would recommend installing SSD on M2_2 for primary operating system drive? I can do that. Then install my four SSD drives from M2_2 through M2_5?

Only one SSD drive had anything on it from previous computer, but I used that as my M2_1 SSD and reformatted and installed Windows 11 on it. The other three were blank and new. What a pain having these five on board SSD slots, and not being simple plug and play.  

[MrAgapiGC]

Use M2_2 for the os. NOTHING on M2_1. and the other as you will.

NOTE: samsung nvmes when are new MOST do not appear on bios per se BUT should appear on TOOLS secure erase. CHECK. IF it does you are set to go. Once windows is install we deal with it later. MAKE SURE the last known bios is install. and make sure csm is disable, secure boot is UEFI and CUSTOM. you will see it.  then install windows. i will be here for another hour 

[Giode]

(see my initial reply above) I just moved my Primary SSD from M2_1 to M2_2. I left M2_1 empty. Now instead of two of my SSD drives appearing, only one appears now. The SSD in M2_3, M2_4, and M2_5 are not showing as installed.

[MrAgapiGC]

one think at the time. check on bios TOOLS , secure erase if are there. i send you a private msg

[Giode]

Thank you for your help! My Bios is the newest that Installed a few days ago. I installed Windows a few days ago and it is up and running on primary SSD. I will go into the Bios and check the things you mention right now.

[Giode]

Unfortunately only M2_2 SSD is showing in Secure Erase. It appears M2_3, M2_4, and M2_5 are not functioning. I disabled CSM and made sure Secure Boot is UEFI and set to Custom. Nada 

[MrAgapiGC]

where is the gpu? check the private msg please

[Giode]

The GPU is located PCIEX16 (G5)_1.