AHCI disabled on XPS 8900 desktop

Hi,

Did you purchase the system with RAID enabled?   You should be able to go into your SATA operations section of your System Setup to change the SATA Operations to AHCI.

1. Press <F2> to enter system setup
2. Expand System Configuration using mouse or arrow keys on the keyboard.
3. Select SATA Oprtation using Mouse or arrow keys on the keyboard.
4. Select the option as required, the options are RAID, AHCI and Disabled.

Let us know if this helps or not.  Please PM me your service tag and I'll see if I can pull up the order number to see if the system had shipped out with RAID enabled from the factory.  But I think the above steps will resolve your issue.

Todd

Hi Todd, thanks for responding.

I purchased the system at Costco. I haven't done anything to the BIOS except choose AHCI. When it boots up, I get the INACCESSIBLE_BOOT_DEVICE error message. After rebooting, the settings are automatically changed back to RAID. From what I've read on the Internet, it's because AHCI is not enabled.

My SSD works with RAID, but I can't optimize it. It has to be set up to run under AHCI.

Thanks again. (My service tag is<ADMIN NOTE: Service tag removed per privacy policy>)

Here's a post on another forum - Enable AHCI after Windows installation You can also do a Google search for the words as there are other methods involving editing the registry. You could also reinstall Windows and update the UEFI before you start the reinstallation.

Hi scgms1,

Thanks for this link.

philipmycar,

Can you try this and confirm whether it resolves your problem or not?

Todd

Hi phillipmycar,

A UEFI/BIOS update won't correct your situation. You didn't list the steps you took when you added the new SSD drive. That would help, but...I'm assuming that you cloned the hard drive and RAID was already set up. I've noticed that some of the cloning software is not making an exact copy of what is on the OEM drive. What did you use? You might notice that instead of EFI partition it is now NTFS. With both drives in the PC go to -

1. Computer Management
2. Storage
3. Disk Management

Do both hard drives show the same EXACT file system on all partitions?

What's checked  in the UEFI/BIOS for

1. Boot Sequence
2. Advance Boot Options

I believe you're running into a couple of problems here -

You don't have an exact copy of the partitions needed. You could always enable Legacy ROM's... & the other issue was the SSD was configured for IDE, not AHCI.

Possibly the simplest way for you to fix this would be to install the OS system again, with AHCI and the UEFI tweaks you want to make before you begin the install process. Windows 10 installs very quickly compared to other OS's I've installed. No need to download the drivers prior to this as Windows does a good job of getting them for you.

Thanks for your response. I used Samsung's data migration software (Clonix). It seemed to work. I was getting disk collisions after the transfer, which tells me each disk looked the same to the system. As to IDE, Dell's BIOS doesn't give you a choice...it's SATA or nothing. You also only get AHCI, RAID, or nothing as a choice. From what I've read so far, AHCI doesn't work if it's not enabled. When I try, I get an INACCESSIBLE_BOOT_DEVICE message, the system errors out, and reboots, resetting AHCI back to RAID. One question I have is why not enable AHCI all the time. How much impact to the system would it have even if you don't use it? Anyway, I have since repartitioned and reformatted my original HD and will use it for a data drive. My SSD is working fine. It is only a little faster than my HD since it runs under RAID. I was hoping to get the "lightning fast" access everyone said I would get, but that's because I can't get AHCI to work. You are probably right. I need to reinstall Windows 10 from scratch. My question there is if it didn't like AHCI after Windows was installed, why would it like it doing a reinstall?

Hi Philipmycar,

You can't simply change SATA controller mode without making the proper OS driver adjustments. This has nothing to do with the BIOS. When you do a fresh installation, the OS installer recognizes the controller mode and installs the proper driver. That's one reason it's easier to do a clean install than clone.

People love to clone to save a couple hours installing the OS, but then waste days trying to fix what didn't work.

Hi Osprey4: Thanks for your response. You're saying if I do a clean install, somewhere in the process the installer will recognize my SSD and set it up under AHCI? That would be great. But what's to stop it from using RAID? I've done several installs from scratch and I don't remember being asked whether I wanted RAID or AHCI, but then again, I didn't have an SSD. The default for an HD was RAID.

I have a new XPS 8900.  I do see my default Sata in the BIOS is RAID.  So my existing internal 1 tb HDD is configured with this setting through Windpws System 10, correct? I want to prepare and soon format a Sata SSD, (Samsung 850 PRO 512GB 2.5-Inch SATA III Internal SSD) which I understand requires ACHI, correct? If I change my BIOS now to ACHI, will my system still see my original installed HDD 1 tb Toshiba drive?  Later I have a Samsung 950 Pro PCIe SSD coming to install which I want to make the start up disk.  Should I just wait and do that with the Samsung migration software to clone my original Win 10 HDD?  OR do I need to change the whole system first to AHCI to accommodate future Sata SSDs?  I hope I can clone my system and files to a startup SSD. I already have a lot of apps and files and local users installed.Thank you...

This worked perfectly.

Both scgms1 and Tom76 got it right, although I used Msconfig instead of bcdedit like Tom76.

I bought a new XPS 8900 directly from Dell, loaded all my applications and files, then replaced the HD with an Acronis cloned Samsung 850 Pro, and was a happy camper, getting really good performance. It wasn't until I ran Samsung Magician that I found out I was in RAID mode! Thanks Dell.....

The switching under Safe Mode worked perfectly.

My Magician performance tests did improved slightly, but wasn't all that bad to begin with using RAID mode. I haven't Optimized or enabled Rapid Mode yet, but will study doing that next.

I have the same issue. Costco system with Raid enabled. I installed a 1TB Samsung SSD and use the original 1TB spinner for backups. Now I need to figure out how to reconfigure and reinstall.... I have another SSD I can clone etc etc etc...