Intel RST / AHCI Guide

Many computers that come pre-installed with Windows default to Intel RST (Rapid Storage Technology) mode. In this mode, the Ubuntu installer may not be able to detect the hard drive. This page explains how to safely switch to AHCI mode.

What Is Intel RST

Intel RST (Intel Rapid Storage Technology) is an Intel storage management solution with the following main features:

Hard drive RAID management
Using Optane memory to accelerate HDDs
SSD caching acceleration

In UEFI settings, the disk controller mode typically offers these options:

RST / Intel RST Premium: Uses the Intel RST driver; the default Windows mode
AHCI: Standard SATA/NVMe controller mode; fully supported by Linux
RAID: Traditional RAID mode

Why Ubuntu Needs AHCI Mode

The Ubuntu kernel does not include the proprietary Intel RST driver
In RST mode, the Ubuntu installer will show “No hard drives detected”
AHCI is a standard protocol natively supported by the Linux kernel with the best compatibility

How to Check the Current Mode

Method 1: Windows Device Manager

Right-click Start -> Device Manager
Expand IDE ATA/ATAPI controllers or Storage controllers
If you see “Intel RST” or “Intel Rapid Storage,” the current mode is RST
If you see “Standard SATA AHCI Controller,” it’s already in AHCI mode

Method 2: UEFI Settings

Enter UEFI settings and check the SATA Mode under Advanced or Storage Configuration.

Safely Switching to AHCI Mode

Warning: Directly switching from RST to AHCI in UEFI will cause Windows to blue screen and fail to boot! You must follow the steps below.

Step 1: Enable Safe Mode in Windows

Press Win + R, type msconfig, and open System Configuration
Switch to the Boot tab
Check Safe boot and select Minimal
Click OK
Do not restart yet

Or use the command line (run as administrator):


bcdedit /set {current} safeboot minimal

Step 2: Switch the Mode in UEFI

Restart the computer and enter UEFI settings
Find the storage controller settings (location varies by motherboard):
- Advanced -> SATA Configuration -> SATA Mode
- Advanced -> Storage Configuration
- Chipset -> SATA Mode Selection
Change the mode from RST / Intel RST Premium / RAID to AHCI
Save settings and exit

Step 3: Boot Windows in Safe Mode

After switching, the computer will boot into Windows Safe Mode. In Safe Mode, Windows will automatically load the AHCI driver.

Step 4: Exit Safe Mode

In Safe Mode, press Win + R, type msconfig
Switch to the Boot tab
Uncheck “Safe boot”
Click OK and restart

Or use the command line:


bcdedit /deletevalue {current} safeboot

Step 5: Verify

After Windows boots normally, open Device Manager and confirm that the storage controller has changed to AHCI mode. Windows should function normally.

Newer Platforms Using VMD Controller

Some newer Intel platforms (11th generation and later) use a VMD (Volume Management Device) controller, which is slightly different:

Checking for VMD

In UEFI settings, look for a VMD Controller or Volume Management Device option.

Solutions

Method 1: Disable VMD (Recommended)

The procedure is similar to switching from RST to AHCI:

Set Windows to boot in Safe Mode
Enter UEFI and disable the VMD Controller
Boot Windows in Safe Mode to install the standard controller driver
Exit Safe Mode and use normally

Method 2: Keep VMD (relying on the kernel’s built-in vmd driver)

Recent kernels (including Ubuntu 26.04) ship with the vmd driver built in, so in most cases the installer can detect the NVMe disk directly even with VMD/RST enabled, without any extra kernel parameters. Boot the installer normally first and check whether the disk appears.

Note

The commonly cited nvme_core.default_ps_max_latency_us=0 parameter is unrelated to VMD disk detection — it is a workaround for certain NVMe SSDs dropping off the bus in the APST power-saving state, and it does not fix a disk that isn’t detected under VMD/RST mode. Do not use it for this scenario.

If the installer still cannot detect the disk with VMD enabled, the most reliable approach is to follow Method 1 and disable the VMD Controller in BIOS/UEFI (or switch the SATA/RST mode to AHCI) so the disk is presented to the system in the standard way.

Brand	SATA Mode Setting Path
Lenovo	Config -> Storage -> Controller Mode
Dell	System Configuration -> SATA Operation
HP	Advanced -> System Options -> SATA Mode
ASUS	Advanced -> SATA Configuration
Acer	Main -> SATA Mode

FAQ

Windows blue screens after switching to AHCI

This means the correct procedure wasn’t followed. To fix:

Re-enter UEFI and change the mode back to RST
Windows will resume booting normally
Follow the complete steps above to redo the process

Can’t find the AHCI option in UEFI

Some computer brands (especially laptops) may hide this option. Try:

Check for BIOS updates; newer versions may add this option
Contact the computer manufacturer’s technical support
Some models may require a modified BIOS (not recommended; risky)

Will switching to AHCI degrade performance?

For NVMe SSDs, there is very little performance difference between AHCI and RST modes. For SATA SSDs/HDDs, AHCI is the standard mode with perfectly normal performance. The only thing potentially affected is an Intel Optane memory + HDD acceleration setup — switching will disable Optane acceleration.

I don’t want to switch modes. Are there other options?

If you don’t want to change the storage controller mode, another option is to install Ubuntu on a separate hard drive or external device, bypassing the RST issue. However, this approach isn’t as clean as switching to AHCI.