Switching from RAID to AHCI

My AW 17 came with a 750 GB HDD and a 60 GB mSATA drive as SSD cache, that configuration necessitated the BIOS setting for the drive controller to be set as RAID.

Upon the failure of the HDD, I decided to replace it with a 500 GB SSD. I opted for a clean Windows install, unfortunately, I forgot to set the controller option to AHCI in the BIOS during the install. It is still set as RAID.

Samsung Magician, the SSD management software that comes with the drive says that to get optimal performance, the drive needs to be set as AHCI, but according to the interface AHCI is deactivated. As a matter of fact, it can't read the SATA interface details. (Which is actually fairly strange when I think iof it, AHCI is supposed to be a subset of RAID)

When I activated AHCI instead of RAID in the BIOS, the laptop BSOD'ed before loading Windows, I applied this solution: Error message occurs after you change the SATA mode of the boot drive without any result. Then again, the proposed solution was for switching from SATA to AHCI, not from RAID to AHCI.

Am I missing something?

I forgot something, I have the exact same BSOD before windows finishes loading even if I try to set it to SATA instead of AHCI.

 

The BSOD on loading widows is usually what happens and although I did see a registry hack to fix it more often it needs windows to be reinstalled. You might find it will start in safe mode where you can remove the disk driver, restart, and hope.

More of a question is why bother? All that stuff about needing AHCI for best performance refers to benchmark speed tests and of course the OEM's want you to see the best numbers. In reality you would not even notice that RAID drivers were loaded, apart from a couple of seconds during load when the RAID BIOS loads.

Keeping it gives you far more flexibility for the future. If you get a large HDD down the line you can reallocate the mSATA to it and speed it up considerably, or add another big SSD and RAID them as a single unit (not recommended IMO due to the fact a single drive failure brings the whole installation down).

It's a one time choice and after windows is installed your pretty much stuck with it.

HTH

 

Easy

Just force the installation of AHCI driver of your controller in windows.

Then, reboot, and go directly to the BIOS, change to AHCI, save and reboot.

Windows will load your AHCI driver as you previously forced installed it manually

 

Are we missing that it has to be in raid for the SSD to cache and .. That the HDD will preform far better in this raid mode with the ssd caching to it. So trying to force this we are taking the ssd out of the equation?

 

Only from the way I read it that the original HDD that was cached is no longer there. The cache drive will end up as a standalone SSD

The suggestion above to force the non-raid driver seems plausible, but I'm not sure it can be forced with the RAID BIOS active

 

How do you do that?
.
I already have Intel RST drivers installed and Device Manager > Storage Controllers shows Intel(R) Mobile Express Chipset SATA RAID Controller (I don't have another storage controller).

Am I missing anything?

I forgot something, I have the exact same BSOD before windows finishes loading even if I try to set it to SATA instead of AHCI.

I've replaced the original HDD with a 500 GB SSD, my BIOS is still set to RAID, I want to set it to AHCI.

 

Windows 7, uninstall Intel RST>Reboot>F2 Enter the BIOS and set it to AHCI mode>F10 save and exit>F8 select safe mode option>Once in safe mode open device manager and check for microsoft AHCI driver>reboot

Windows 8, cmd (admin) type/enter :

Code:

bcdedit /set {default} bootmenupolicy legacy

Uninstall Intel RST>Reboot>F2 Enter the BIOS and set it to AHCI mode>F10 save and exit>F8 select safe mode option>Once in safe mode open device manager and check for microsoft AHCI driver>reboot.

AHCI: Intel® Rapid Storage Technology Driver for Intel Desktop Boards



View attachment 101002

 

RAID is better than AHCI. RAID provides AHCI function for drives that are not in a RAID membership. Solution: Ignore the message and uninstall Samsung Magician. You don't need it for anything.

 

Didn't work, I followed your procedure until the safe boot part, I saw the list of drivers loading, and the it crashed the exact same way.

I also don't have an ide/atapi controller anywhere in Device Manager.

 

Just a question, but from my understanding, you originally had a 750gb HDD cached by the 64gb mSata. You replaced the HDD with a SSD which is understandable. Why are you not utilising the 750gb HDD in the other slot? - I mean, it's a waste if it's just being chucked in a drawer when you could have it in your machine, still being cached by the mSata. End result being that you have genuine 500gb SSD storage AND 750gb of 'SSD-like' storage.

Seems like a no brainer to me. Leave the bios set to raid (so you can use the mSata to cache the HDD) and just run things like that. There is very little point in wasting a good large HDD and the mSata just so you can install the OS to the SSD under AHCI mode - the only tiny benefit of doing that is a few seconds off boot time when you don't see the option to enter the raid configuration menu upon booting.

If the original HDD failed, just get it replaced by Dell as surely you're still under warranty with your new machine.

Just my two pennies...

 

Backup first, if it doesn't work you'll need to reinstall windows.

BIOS>set RAID option>F10 reboot.

Back in windows, cmd (admin).

Code:

bcdedit /set {current} safeboot minimal

Device manager>RAID Controller>uninstall / check delete the driver software for this device>reboot>BIOS set AHCI mode>F10 reboot (don't use F8)>safe mode>check ide ata/atapi AHCI.

Safe mode, cmd (admin).

Code:

bcdedit /deletevalue {current} safeboot

>reboot.

 

Thank you, but I think I'll give up for now, sequential read/writes as well as random read/writes are currently all above 95% of their theoretical maximum, so I think I'll leave it in its current state.

And, I'll probably use the warranty to get a new drive.

 

Just an update, I found out why it crashed in AHCI mode, it didn't load the atapi driver. A change of the Start value from 3 to 0 in the register for HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\atapi solved the issue.