[Boot Problem] SATA SSD Not Detected when CSM is Disabled

underearth12 · January 1, 2026, 4:51pm

Hi everyone,

I’m trying to enable Secure Boot on my ZSUS X99-W motherboard (with an Intel Xeon E5-2680 v4).

When CSM is enabled and Storage Boot Option Control = Legacy:

-> My SATA SSD is fully visible in the boot menu and works perfectly.

When CSM is disabled (required for Secure Boot) or when in CSM Support → Storage = UEFI:

-> The exact same SSD completely disappears from PCH SATA Configuration (see screenshot). As a result, even though “Windows Boot Manager” may still appear in the boot options, the system cannot actually boot from it and loops back into the BIOS.

Windows is installed in UEFI mode

The drive is formatted as GPT

SATA mode is set to AHCI (not RAID)

This is not a Windows or partition issue the SSD is fully functional and bootable when forced via Legacy. The problem is purely BIOS-side: the UEFI firmware fails to enumerate the SATA drive when CSM is off.

System Details:

Motherboard: ZSUS X99-W

CPU: Intel Xeon E5-2680 v4

SATA Mode: AHCI

SSD: SATA (not NVMe), GPT partitioned

Target: Enable Secure Boot → requires CSM = Disabled

UBU Analysis:

I analyzed my stock BIOS using UEFI BIOS Updater (UBU) and found the following:

Scanning BIOS file bios-x99-w-zsus-original.rom.

Please wait…

Manufacturer - INTEL

Model -X99-W

BIOS release - 5.11 12/04/2024

BIOS version - 00.01

BIOS platform - AMI Aptio 5

[EFI Drivers - Find and Extract]

Intel RST GUID 91B4D9C1-141C-4824-8D02-3C298E36EB3F

AMI NVMe GUID 634E8DB5-C432-43BE-A653-9CA2922CC458

Realtek Undi GUID 32D4B2DD-1DB3-4AF9-91B0-FBAE6E6EA259

[OROM - Find and Extract]

OROM in GUID 365C62BA-05EF-4B2E-A7F7-92C1781AF4F9

OROM in GUID A0327FE0-1FDA-4E5B-905D-B510C45A61D0

OROM in GUID A0327FE0-1FDA-4E5B-905D-B510C45A61D0

Main Menu

[Current version in BIOS file]

1 - Disk Controller

EFI Intel RST RAID Driver - 14.8.0.2377

OROM IMSM RAID for SATA - 8.9.0.1023

OROM Intel RSTe for SATA - 4.5.0.1012

OROM Intel RSTe for sSATA - 4.5.0.1012

EFI NVMe Driver present

2 - Video OnBoard

3 - Network

EFI Realtek UNDI Driver - 2.037

OROM Realtek Boot Agent GE - 2.66

4 - Other SATA Controller

5 - CPU MicroCode

View/Extract/Search/Replace

S - AMI Setup IFR Extractor

O - Option ROM in other GUIDs

0 - Exit

RS - Re-Scanning

A - About

Choice:

Disk Controller

[Current version]

EFI Intel RST RAID Driver - 14.8.0.2377

OROM IMSM RAID for SATA - 8.9.0.1023

OROM Intel RSTe for SATA - 4.5.0.1012

OROM Intel RSTe for sSATA - 4.5.0.1012

[Available version]

EFI Intel RST RAID Driver - 14.8.2.2397

OROM Intel RST for SATA - 14.8.2.2397

EFI Intel VROC for SATA - 6.1.0.1017

EFI Intel VROC for sSATA - 6.1.0.1017

OROM Intel VROC for SATA - 6.1.0.1017

OROM Intel VROC for sSATA - 6.1.0.1017

1 - Replace

2 - Replace only RST

3 - Replace only RSTe/VROC

X - Extracted

0 - Return to Main Menu

Choice:

Request for Help:

How can I make my SATA SSD properly detected and bootable in UEFI mode with AHCI, without relying on CSM?

Should I replace the EFI Intel RST RAID Driver in my BIOS to get SATA SSDs detected in pure UEFI mode (with CSM disabled)?

If yes, what is the correct replacement driver ?

Thanks in advance!

Edit by Fernando: Thread title shortened and customized

Koekieezz · January 1, 2026, 5:11pm

Is the sata boot drive is initialized as GPT rather than MBR?

underearth12 · January 1, 2026, 6:32pm

Yes, GPT is required for UEFI boot, and my drive is indeed formatted as GPT.

Fernando · January 1, 2026, 6:55pm

@underearth12
Happy New Year and welcome to the Win-Raid Forum!

No, the Intel RAID EFI module is not used at all by your system, because the Intel SATA Controller is running in AHCI mode.
By the way - which OS are you running?
Question: What happens, if don’t enable “Secure Boot” within the BIOS?

underearth12 · January 1, 2026, 7:30pm

Happy New Year and thank you for your help.

I’m running Windows 11 (version 25H2), installed in UEFI + GPT mode on a SATA SSD.

Actually, I don’t need to enable Secure Boot the issue occurs even when Secure Boot is off. The SSD disappears from the PCH SATA Configuration as soon as:

CSM Support is fully disabled, or CSM Support is enabled, but Storage is set to UEFI (instead of Legacy).

I only want to use pure UEFI mode to eventually enable Secure Boot, because a specific game requires it. But Secure Boot itself isn’t causing the problem the real issue is that the SATA controller simply doesn’t expose the drive in UEFI mode when running in AHCI, even though AHCI is the correct and intended mode for a single SSD.

Now, regarding the UEFI BIOS Updater:
In the “1 - Disk Controller” section, I see:

1 - Disk Controller

EFI Intel RST RAID Driver - 14.8.0.2377

OROM IMSM RAID for SATA - 8.9.0.1023

OROM Intel RSTe for SATA - 4.5.0.1012

OROM Intel RSTe for sSATA - 4.5.0.1012

EFI NVMe Driver present

There’s no dedicated UEFI module for standard SATA AHCI drives only RAID and NVMe.
This makes me think the BIOS relies on the Intel RST RAID UEFI driver even in AHCI mode, which likely explains why standalone SATA SSDs aren’t enumerated in pure UEFI.

Do you have any idea what I should do?
Is there a driver I can safely inject via UBU to make SATA drives visible in UEFI mode without RAID or CSM?

Fernando · January 1, 2026, 8:25pm

Indeed, an AHCI EFI BIOS module has never been released by Intel. Only Intel AHCI Option ROM modules heve been released, but none of them will help you while running the OS in UEFI mode.

underearth12 · January 1, 2026, 10:43pm

It’s surprising that Intel never released a EFI module for standard SATA AHCI.

So, does that mean motherboard vendors like MSI, ASUS, or Gigabyte had to develop their own UEFI AHCI modules to offer AHCI support in UEFI mode for SATA ?

Also, if native AHCI UEFI support isn’t provided by Intel, are my only real options either:

Switch from AHCI to RAID mode, so my SATA drive works in pure UEFI mode or keep AHCI mode but use an NVMe drive instead of my SATA ?

Fernando · January 1, 2026, 11:11pm

@underearth12
Booting off a SATA AHCI Controller in UEFI mode should be natively supported by all mainboards (no AHCI EFI BIOS module is required).
So I suspect, that your issue is hardware related. You should ask the ZSUS Support for help.

I would prefer booting off an NVMe SSD, if your problem cannot be solved by the manufacturer of your mainboard.

underearth12 · January 2, 2026, 9:59am

I’ve already tried searching unsuccessfully for either an official or unofficial website offering a newer BIOS version for my motherboard. The issue is that it’s a Chinese brand, Zsus, and I can’t find any reliable resources online: no manufacturer’s website, no firmware, and no technical documentation.

Tris · January 2, 2026, 10:24am

Such a weird issue you have here - SSD detection alone should have nothing to do with CSM. Can you try to load BIOS defaults → restart → change Video in CSM menu to UEFI → restart → disable CSM, then plug in your SATA drive?

And btw have you tried other SATA ports? I can also see some NVME/SATA M.2 jumper near the M.2 port, could it be that you accidentally plug the SSD to the SATA port which has been disabled by the jumper to enable SATA mode in M.2 port?

underearth12 · January 5, 2026, 5:36pm

I’ve tested all three SATA ports I have, but the drive isn’t being detected when I set the storage controller to UEFI mode. I even tried switching the PCH SATA Configuration from AHCI to RAID, and enabled the option to load the EFI/UEFI driver (I don’t remember the exact name), but the drive still isn’t showing up. Does anyone have another solution besides using an NVMe drive?

Tris · January 6, 2026, 1:32am

Have you a CH341A? If yes, then I think you can try to crossflash BIOSes from other Chinese LGA2011-3 boards with the same H55/HM55 chipset.
You can prolly start with this.

underearth12 · January 6, 2026, 10:56am

I checked the BIOS with UEFI BIOS Updater, and here’s what it contains:

Scanning BIOS file X99P4002.rom.
Please wait…
Manufacturer - INTEL
Model - X99-P4
BIOS release - 5.11 11/19/2025
BIOS version - 00.02
BIOS platform - AMI Aptio 5
    [EFI  Drivers - Find and Extract]
Intel RST GUID 91B4D9C1-141C-4824-8D02-3C298E36EB3F
AMI NVMe GUID 634E8DB5-C432-43BE-A653-9CA2922CC458
Realtek Undi GUID 32D4B2DD-1DB3-4AF9-91B0-FBAE6E6EA259

1 - Disk Controller
EFI Intel RST RAID Driver - 14.8.0.2377
OROM IMSM RAID for SATA - 8.9.0.1023
OROM Intel RSTe for SATA - 4.5.0.1012
OROM Intel RSTe for sSATA - 4.5.0.1012
EFI NVMe Driver present

The BIOS you gave me has exactly the same disk controller drivers as my original BIOS. Check:

Scanning BIOS file bios-x99-w-zsus-original.rom.
Please wait…
Manufacturer - INTEL
Model - X99-W
BIOS release - 5.11 12/04/2024
BIOS version - 00.01
BIOS platform - AMI Aptio 5
    [EFI  Drivers - Find and Extract]
Intel RST GUID 91B4D9C1-141C-4824-8D02-3C298E36EB3F
AMI NVMe GUID 634E8DB5-C432-43BE-A653-9CA2922CC458
Realtek Undi GUID 32D4B2DD-1DB3-4AF9-91B0-FBAE6E6EA259

1 - Disk Controller
EFI Intel RST RAID Driver - 14.8.0.2377
OROM IMSM RAID for SATA - 8.9.0.1023
OROM Intel RSTe for SATA - 4.5.0.1012
OROM Intel RSTe for sSATA - 4.5.0.1012
EFI NVMe Driver present

But I found this BIOS:
http://www.huananzhi.com/attach/Drive/X99-P4Drive/X99-PV1.023-7-19.rar

X99-PV1.023-7-19.rar (4.4 MB)

I check what’s inside it using UEFI BIOS Updater.

Scanning BIOS file X99P4V10.rom.
Please wait…
Manufacturer - HUANANZHI
Model - X99-P4
BIOS release - 5.11 07/19/2023
BIOS version - 00.04
BIOS platform - AMI Aptio 5
    [EFI  Drivers - Find and Extract]
Intel RST GUID 91B4D9C1-141C-4824-8D02-3C298E36EB3F
Intel RSTe SubGUID C9352CC3-A354-44E5-8776-B2ED8DD781EC
Intel RSTe SubGUID 224D6EB4-307F-45BA-9DC3-FE9FC6B38148
AMI NVMe GUID 634E8DB5-C432-43BE-A653-9CA2922CC458
Realtek Undi GUID 1A7828FC-DA7D-4BC1-8B58-9A954FED7D70
Realtek Undi SubGUID 1A7828FC-DA7D-4BC1-8B58-9A954FED7D70
Realtek Undi SubGUID 1A7828FC-DA7D-4BC1-8B58-9A954FED7D70

1 - Disk Controller
EFI Intel RST RAID Driver - 14.8.0.2377
EFI Intel RSTe for sSATA - 4.5.0.1012
EFI Intel RSTe for SATA - 4.5.0.1012
OROM Intel RSTe for SATA - 4.5.0.1012
OROM Intel RSTe for sSATA - 4.5.0.1012
EFI NVMe Driver present

Right now, I’m trying to add these two drivers into my original BIOS:

EFI Intel RSTe for sSATA – 4.5.0.1012
EFI Intel RSTe for SATA – 4.5.0.1012

I think this is what I need to get UEFI SATA support working in AHCI mode, right?

But when I open the BIOS with MMTool_a5.exe, I see that both “EFI Intel RSTe for SATA” and “EFI Intel RSTe for sSATA” are listed under Option ROM.
My problem is: I can’t figure out how to add them with the same Device Path like they did. So I’m stuck.

Tris · January 6, 2026, 1:19pm

That X99-P4 BIOS from Huananzhi is for the variant with H81 chipset. Yours is H55/HM55, and I have checked several other BIOSes with HM55/H55 chipset - they all share the same Disk Controller modules. I guess there’re some fundamental differences between H55 and H81 BIOSes in terms of these modules (since the PCH controls the SATA ports). Anyway, you can try to transplant only the BIOS region from Huananzhi X99-P4 to your original BIOS (using UEFITool 0.28 replace-as-is function) and flash to see if it somehow works.

Side note: AFAIK, when you disable CSM, all the Option ROMs will be of no use - they are only for Legacy mode.