6 Replies Latest reply on Aug 17, 2011 9:16 PM by Boyet

    Enabling AHCI in Win7 64bit


      I have found out how to enable AHCI in Win 7 64bit once the OS is installed, my question is once AHCI is enabled, does it effect all other hard drives connected? If not, how do I enable AHCI to see the other drives? Right now, in Win7 Device manager it's reporting, under IDE ATA/ATAPI Controllers:

      Standard AHCI 1.0 Serial ATA Controller

      Standard Dual Channel PCI IDE Controller


      My motherboard is a P55 FTW 200, P55 chipset

      Thanks in advance

        • 1. Re: Enabling AHCI in Win7 64bit

          I believe whe you enable AHCI, it effect all ports on that controller, as well as the HDDs connected. It seems you're already in AHCI mode, but I'm not sure where this IDE Controller comes from. You can view the devices by connection in Device Manager so that you'll understand which HDDs are controlled by the AHCI controller.

          • 2. Re: Enabling AHCI in Win7 64bit

            AHCI is controlling only "C" drive (red box, Fig 1), the PCI IDE controller is probably controlling the other two disks as well as the CD/DVD. I don't know how AHCI would behave on my other two external SATA drives as of yet but after doing some googleing on this subject as well as posting in the Windows 7 forums and the EVGA forums, I'm getting the feeling than the only way you can enable AHCI on all drives and maybe even my external drives, is to do a clean install of Win 7. I hate to do this again and was hoping that I could get AHCI enabled without the re install. Also, there is another problem occurring, possibably because of this, and that is "C" has been kicked out of P0 and is now P2 (fig 2). I found that even if you move your SATA connectors to different SATA ports, if you use DISKPART and make "C" an active partition(even though it already is), C will stay in the same position. I've been told that if you have to re install Win 7, you have to disconnect any other hard drives prior to re install. This forces "C" to be in P0. Maybe I'm wrong, but I'm getting the feeling that AHCI, even though benificial, may be causing a big problem at the same time. I don't and won't know until I can get AHCI working on all drives.

            Fig 1 - AHCI controller.jpgFig 2 - Disk position.jpg

            • 3. Re: Enabling AHCI in Win7 64bit

              If you run AS SSD and select the drive you want, you will see which drive is in MSAHCI mode.

              • 4. Re: Enabling AHCI in Win7 64bit

                Boyet: I have no clue what AS SSD is[dummy me] but I already know what drive is being controlled by AHCI, that being "C" as shown in my first pic with the box around it. Now, here's my quandry, With the BIOS being configured as IDE, all drives are being reported as SATA. With AHCI enabled only one drive is being reported as SATA and the other two are being reported as HDD. The question I'm asking is "Once AHCI is enabled in the BIOS and the hard drive is formated in Win7 and is installed(clean) do ALL drives come under AHCI? If you enable AHCI once the OS is installed, how do you get the other drives to be under AHCI?

                Now, here's another little tid bit, if you notice in my second pic, the one with the drives, you'll notice that "C" drive is now disk 2. If something should happen, like loosing your MBR, which happened to me, I put the Win7 in by  DVD drive and went to repair, and guess what, Windows could not find an operating system, you know, in the box which asks you which operating system do you want to repair? It couldn't find it cause it was not at P0. Also, everyone keeps saying that if you have to do a repair or anything with Win7(I'm guessing Vista as well, I dont know) you have to disconnect your other drives so Windows can do its thing. This makes no sense to me at all. You're primary drive is connectd to SATA port 0, your BIOS shows what disk is at P0, which is your C and OS yet because of AHCI it gets pushed out of position. Thats why all drives, I feel should be under AHCI not just one.

                • 5. Re: Enabling AHCI in Win7 64bit

                  AS SSD is a benchmark program. It display the info of the drive selected including ahci mode op.


                  I have the chipset-sata mode in the bios set to ahci and I can see all the drives including optical drives assigned to the mb ports. In windows device manager, there is only one ahci controller shown unlike in your case where you have the ide controller (maybe it is a separate pci card?). From this I would assume that all my drives are in ahci mode. Running the AS SSD program confirms that my two drives (ssd and hdd) are in msahci mode.


                  After the above setup I have set my ssd as a uefi boot disk and examine the list of drives in the bios. This time all the drives are still shown except for my hdd which is an mbr drive and one optical drive specifically labelled as AHCI Drive. Although the hdd is not shown in the bios, running AS SSD still confirms that it is in ahci mode.


                  As a summary, setting the chipset-sata mode to ahci will cause all drives to operate in ahci mode. Exception to this might be the existence of a pci ide card controller.


                  Message was edited by: Boyet

                  • 6. Re: Enabling AHCI in Win7 64bit

                    Once you enabled AHCI in BIOS, all ports and HDDs on that controller are in AHCI mode. I did some researches and noticed your board has a total of 8 SATA ports (including eSATA). The P55 PCH has 6 SATA ports, which means you may have a second SATA controller on you board. If you connect HDDs on that second controller, you may need to enable AHCI on that controller seperately.