Can I set AHCL in BIOS before a clean install of WIndows 11?

Topic

New Reply

[RetiredGeek]

I’ve seen a couple posts about this elsewhere. One said it’s fine to set the controller to ACHI
before a clean install; but then I saw another that said it led to a blank blue screen during the installation process.

I’ve changed from RAID to ACHI without reinstalling Windows 10 before, and I saw that the same can be done with Windows 11, so I could do that if needed.

• This topic was modified 1 year, 8 months ago by RetiredGeek. Reason: Changed ACHL to ACHI
• This topic was modified 1 year, 8 months ago by RetiredGeek. Reason: That's ACHI

Reply | Quote

Replies

Before a clean install there’s no issue whatsoever. You can sometimes get an INACCESSIBLE_BOOT_DEVICE BSOD if you change the mode after installation, but you can usually get around this by booting Windows in safe mode.

1 user thanked author for this post.

Seattle27

Reply | Quote

RAID and AHCI seem to give the same performance and Dell ships desktops with RAID enabled – maybe in case you want to use it.

I would leave it alone and re-install, after making an image backup of course.  🙂

cheers, Paul

 

Reply | Quote

Paul T wrote:

RAID and AHCI seem to give the same performance and Dell ships desktops with RAID enabled – maybe in case you want to use it.

I would leave it alone and re-install, after making an image backup of course.  🙂

cheers, Paul

 

I prefer to disable RAID mode when not needed. It eliminates the need for third-party storage drivers.

Reply | Quote

Unfortunately, many PCs are coming with no option to disable the Intel RST (Rapid Storage Technology mode, also known as RAID mode in some UEFIs). My Acer Swift Go 14 is one of those.

Fortunately, as you mentioned, I have seen no performance difference with it on or off. Using the 6.4 Linux kernel, I’ve tested both idle and loaded power usage (playing a 1080p60 video on loop) on the XPS, and run a few benchmarking runs with Kdiskmark (the Linux clone of CrystalDiskMark), and there is no difference I can see. I would expect the same to be true in Windows, with the exception that one cannot simply switch the UEFI option and be done with it (the standard advice is that you need to reinstall Windows, but I understand there are workarounds to switch Windows over with a lot less trouble for the techie types). I would, though, opt to disable RST if I was going to install Windows cleanly for the reason @steeviebops mentioned. But if that was not feasible, I would not be too upset about that either.

Dell XPS 13/9310, i5-1135G7/16GB, KDE Neon 6.2
XPG Xenia 15, i7-9750H/32GB & GTX1660ti, Kubuntu 24.04
Acer Swift Go 14, i5-1335U/16GB, Kubuntu 24.04 (and Win 11)

Reply | Quote

You still need 3rd party drivers for AHCI, but drivers are added to the Windows install by the manufacturer. If you use an ISO from MS there is a chance that the drivers will not be available for newer machines.

cheers, Paul

Reply | Quote

Paul T wrote:

You still need 3rd party drivers for AHCI, but drivers are added to the Windows install by the manufacturer. If you use an ISO from MS there is a chance that the drivers will not be available for newer machines.

cheers, Paul

There hasn’t been a need for third-party AHCI drivers since XP. AHCI is a standard so once the disk controller exposes the correct device class ID (PCI\CC_010601), Windows will just use its own storahci.sys (msahci.sys in Vista or 7) and nothing else is needed. Any third-party drivers in the Windows image would be for proprietary RAID or SCSI controllers.

Reply | Quote