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Windows 7: SSD had OS installed without AHCI on, can problems arise?

19 Jan 2014   #1

Windows 7 Professional 64-bit
SSD had OS installed without AHCI on, can problems arise?

Basically I had AHCI enabled in the BIOS but it turns out that the SATA port was not one that supported AHCI. I found this out a few days after the installation and changed ports, and AHCI is on just fine and appropriate registry keys adjusted themselves (I checked). I was wondering if problems can still arise and if I am not getting the most performance out of my drive possible.

Someone on a Battlefield forum told me "Except it doesn't work right. Some of the AHCI functions don't work and satiability issues can still happen. If you're going to use AHCI, you need to have it enabled when the OS gets installed. Doing it later doesn't work right, even if you manage to get it to boot."

But I trust people here more. Any advice is appreciated. I am a bit hesitant to wipe the drive and reinstall Windows because I don't want unnecessary writing to my SSD and I also do not want to have to reinstall all my programs and games on my secondary HDD again.


Side note: wasn't sure where this would be appropriate to post, as I originally put it in Hardware but thought this may be more appropriate. Sorry if I am wrong

My System SpecsSystem Spec
19 Jan 2014   #2

windows 7 32bit

Advanced Host Controller Interface - Wikipedia, the free encyclopedia

Boot Issues

Some operating systems, notably Windows Vista and Windows 7, do not configure themselves to load the AHCI driver upon boot if the SATA-drive controller was not in AHCI mode at the time of installation. This can cause failure to boot, with an error message, if the SATA controller is later switched to AHCI mode. For this reason, Intel recommends changing the drive controller to AHCI or RAID before installing an operating system.[1] (It may also be necessary to load chipset-specific AHCI or RAID drivers — from a USB flash drive, for example — at installation time.)
On Windows Vista and Windows 7, this can be fixed configuring the msahci device driver to start at boot time (rather than on-demand). Setting non-AHCI mode in the BIOS will allow the user to boot Windows, where the required registry change can be performed. The BIOS can then be changed to AHCI.[3]
On Windows 8 and Windows Server 2012, the name of the controller has changed from msahci to storahci,[4] and the procedure to upgrade to the new controller to it is similar to that of Windows 7.[5] On Windows 8 and Windows Server 2012, changing the SATA mode to AHCI without updating the registry will make the boot drive inaccessible.

Although not precisely what you described, it's essentially the same. Installed in non-AHCI mode, then switched to AHCI, and it appears that the only issue is whether or not you boot.
My System SpecsSystem Spec
19 Jan 2014   #3

Windows 7 Professional 64-bit

I was hoping for info outside of Wikipedia lol, but thanks I read that too though. The person who originally made me ponder my situation mentioned I might not have all of AHCI's functionality even if it boots, which is what concerns me.
My System SpecsSystem Spec

20 Jan 2014   #4
Microsoft MVP

Windows 7 Ultimate X64 SP1

All AHCI gives you is hot swapability, which you won't do with the OS drive, and Bit Locker use, a w7 encryption. The SSD performance is the same.
My System SpecsSystem Spec

 SSD had OS installed without AHCI on, can problems arise?

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