Windows 10: Attn. SSD owners - Enabling AHCI mode AFTER Windows 10 installation.

I bought a new XPS 8900 directly from Dell, loaded all my applications and files, then replaced the HD with an 850 Evo 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!

The switching under Safe Mode worked perfectly, although I just used Msconfig instead of BCD command.

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.

It was Too Good Toobad. *Thumbs

 

Worked like a charm!

-My older Dell Latitude E6520 was upgraded to Windows 10 recently from win 7. Today replaced the HDD with Samsung 850 Pro and restored from image. Tinkering in the Magician software I noticed the AHCI was not enabled so i was merely getting like 500MB/s read/write performance (exponentially better than my HDD, but not full capacity of my new SSD!) Had the same "Inaccessible boot device" problems and went back and forth several times from AHCI to RAID. I went back to the original MS KB you referenced and got a better understanding of what was going on and why this solution worked/works.

T H A N K Y O U!!!

 

Registered just to say Thank You.

 

As i read all the stuff i noticed some AMD users having some problems while trying to change to AHCI. As AMD user i will also try and share here if it works but before i try i would like to know the worst case scenario.

If it can not damage some components like chipset or ssd(just the Windows software is okey) i will give it a shot since i already made a system image to my external harddrive.

 

Ahci drivers for AMD systems come with GPU drivers and appear in registry by it's name.

 

I tried this an hour ago and everything is fine so far.

Thanks for the trick Toobad!

 

I have ASUS S400CA laptop. It came with HDD. I changed it to SSD in windows 8.1 itself and upgraded to windows 10. I am not sure what was the state before anniversary upgrade. Now UEFI shows SATA mode as AHCI(option AHCI/IDE). But Samsung magician says Deactivated (IDE or RAID). AHCI Mode required for the best SSD performance. I went through these pages and checked and updated Intel drivers. It did not show any update for AHCI. Further regedit showed that there is no msahci in HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services.
How to proceed to set the magician right for AHCI.

 

@lvghandi some systems using Magician have problems since AU , you do not need Magician though so it can be uninstalled .

see this thread about it here:
Widespread AHCI issues in Samsung Magician since Win10 1-year update - Windows 10 Forums
or
does samsung magician show ahci disabled with signed driver error on - Windows 10 Forums

 

Thanks for the response.

 

Just posting to say this worked for me, with Windows 10 and an Sandisk Ultra 960GB SSD:
I'd forgotten to enable AHCI in my ASRock motherboard when I installed the OS.

The only thing I did differently was not use the tedious command prompt method of switching to safe mode.
Instead, I pounded frantically on shift-F8 the moment the BIOS screen finished loading, like a real man.

 

If you cannot boot after the change, CHECK you BOOT DRIVE settings in BIOS. My normal boot drive changed after I changed to AHCI so I had to change it back and it then worked.

 

I successfully used this approach to switch my motherboard SATA setting from AHCI to RAID. In the process, my login switched to password mode but it was easily switched back to PIN mode by clicking on the text underneath the password text box.

 

Your command for safe mode does not work for me. Is that the exact syntax?

 

Worked a treat for me on Gigabyte GA78-LMT-USB 3 V 6 MB AMD FX-8320CPU and WD Blue 500 HDD!
Now to try it on the Toshiba drive! (I use a drive tray and swap drives).

Big thank you!!! Saved me a lot of trouble!

Does anyone know if this method works for Win 7?

 

ya it works, did it a few months back on this PC,

Thanks a bunch.......*Cool