1. What this is about This is about the installation of AHCI drivers to SATA ports for Windows. AHCI drivers (Advanced Host Controller Interface klick -> http://de.wikipedia.org/wiki/Advanced_Host_Controller_Interface for Wiki) are advanced performance drivers for the SATA controller in your mac pro (ICH10R chips for Nehalem - ESB2 for all others). When you go to profiler in OS X and bring up ATA you will see that your disks will all be connected by AHCI protocols. Windows natively uses legacy drivers instead of AHCI when you install it. It expects a BIOS command to select the AHCI mode. On a BIOS machine you simply use a software switch to select the configuration. On an EFI machine as the Mac, you have to manipulate the boot mechanism because the firmware has no user adjustable features. You actually edit your Master Boot Record (MBR) inside the GUID or MBR partition table with a terminal script. I will come to that later. If you are making a fresh installation of Windows from the install disk you can pre load the AHCI drivers from the floppy facility (check the download link in section 3). In Vista and Win7 you do this from the installation window where you can format or partition drives. In XP you have to hit the F6 key in the beginning when XP starts to load from the optical disk. This tutorial is based on the instructions from Ludachris at http://www.insanelymac.com/forum/index.php?showtopic=126089&hl= Many thanks to him. The shell script for the MBR patch is made by Johnsock. http://www.insanelymac.com/forum/index.php?act=attach&type=post&id=49096 Also a big thank you to him. 2. Some potential traps to avoid Some people like to use a unused ODD-SATA port for a Windows HDD or SSD. This is possible as soon as the AHCI driver is working. In order to make the AHCI installation you need to fit the Windows drive to a standard HDD port and make the installation according to section 5. There is a bummer which may hit you if you already use a SW RAID in OS X with a pre 2009 machine. An OS X software RAID array prevents Windows from recognizing other SATA drives as internal. The installation program will tell you that you are installing to an external drive although you are setting your Windows drive properly up on one of the # 1-4 HDD bay. To work around this problem you can physically remove the RAID disks and put them away for a moment . After installing Windows you can put the array back in and it will run without a problem again, so you need not be concerned to remove the array temporarily. To substitute for your now missing array clone OS X to a single disk before you remove your array and when you have it taken out, fit that disk. Then you do your Windows installation stuff. When you are finished with Windows you remove the single disk and refit your array. The 64-bit varieties of Vista and Win7 have 32-bit emulations installed which will allow you to run any 32-bit program. So they are much better to use. A word of warning to 2006 and 2007 Mac Pro owners. Your machines use a 32-bit EFI. It will not be able to read Windows install DVDs with multiple images like the anytime upgrade DVDs. The 32-bit EFI boot loader freezes when you try to load an install disk with multiple images. Known workaround at this time use Jowie's tweak or a similar method to make the file variables palatable to the EFI32 boot loader. http://forums.macrumors.com/showpost.php?p=8513769&postcount=21 3. Preparations Download the Intel Matrix Storage Manager http://www.intel.com/support/chipsets/imsm/index.htm from this adress. If you run XP you also need the floppy disk facility that you find there. The executable we will need very much later when we are practically done changing the MP to AHCI but get hold of it for now. Intel have reported that there was a Vista installation issue with their chips driver (Intel Matrixs storage) up to version 7.0. It is therefore recommended to use 8.8 now. Win7 is officially only supported by 8.9. When you have made those downloads put the folder with the floppy facility on a USB stick or burn it on CD. If you are hell bent to use XP you will actually need floppies because XP will not let you use other means. Generally XP isn't desirable on a Mac Pro because it is only supported in 32-Bit and not in 64-Bit which will make most of your RAM (above 2 GB) memory useless. Copy the zipped file with Johnsock's shell script which is attached to this posting to your OS X drive. You have to unzip it for use. Next go to disk utility in OS X and make a list of the identifiers of your installed drives. You can right click the drive name or use the info button which tells you the internal name of each drive. If the drive is shown as disk2 note it with the extended code form that the shell script uses ( /dev/disk2 ). Make a paper record of that full name of the disk and make sure you copy exactly that code. You will need this later when you may have no access to disk utility and are doing some delicate terminal work. Finally at this point make a backup of your Windows installation if you care for it. You can use Winclone (free software) for the back up or at minimum set a restore point for Windows to get back to that version if you screw up the next step. Restore points can be set when you enter the program section where you find all the Windows internal backup and restore stuff. There are reports that the MP3,1 model from 2008 cannot be put into AHCI mode normally. But some users succeeded by exchanging their optical drive from IDE to SATA or removing it completely before trying to boot Windows from the ODD-SATA ports. So it is recommended to take out any IDE drive. 4. A refresher about other drivers When you have installed Windows load your Apple related drivers from the hybrid Leopard disk. All Leopard disks have a Bootcamp driver image on them which is acessible under Windows only. For 64-bit Windows you need to execute Bootcamp64.msi with admin rights. You find it in the drivers/apple folder on the leopard/SL disk. If it is not there you have a very old version and need to source those drivers somewhere from the internet. There are torrents and downloads from rapidshare available. Google Bootcamp 2.0.1 for that. In Win7 you have to apply the compatibility patch to Vista drivers before you can load the program. To get to compatibility mode right click the file and select the routine for compatibility. When you are done with the general Windows drivers and have installed all the Windows updates you will still need to activate the AHCI drivers for optimum performance. They will not be running at that stage. 5. This is the actual installation 5.1 Editing the registry Now in case we use Vista or Seven we are going to edit the Windows registry as directed by Ludachris. This only needs to be done in Vista and Seven but not in XP because XP has no MS AHCI driver in the standard. This does not yet activate the AHCI driver. If you have pre loaded the Intel driver during the Windows installation it will load a better Intel legacy driver instead of the slow IDE. You can shut down and restart Windows now. 5.2 Installing the driver After this reboot comes the tricky part. We will force Windows to take an AHCI driver, which it normally rejects and we will patch the master boot record (MBR) of the drive that holds the Windows installation. In Windows device manager go to IDE/ATA devices. 2006, 2007 and 2008 Mac Pros have one device for the SATA ports; so its no question which to use. 2009 machines have two separate devices for the ODD and the HDD ports. Select the 4 port HDD device for the AHCI updating. Click properties and update the legacy driver to either the Microsoft or the Intel AHCI driver. It doesn't really matter which one you use. This AHCI installation cannot be done in automatic driver search mode. You have to tell Windows to look in the IDE ATA controller category for them. To find the MS AHCI 1.0 driver in Vista and Seven go to the manufacturer selection and look for Standard. You will have to scroll down to find it. For XP you have to load the Intel driver from from the Intel manufacturer list. If you havn't pre loaded the Intel drivers you should now use the Floppy utility you downloaded. Load these files from USB floppy or USB stick by clicking the have disk option. For pre 2009 you need to select the ESB2 driver. For Nehalem use the ICH10R driver. After this you must not reboot into Windows until you have patched the MBR. Force Windows to take this driver even if it thinks it is incompatible. It actually is but we will soon take care of this with the patch. 5.3 Patching the MBR in OS X The next step is executing Johnsock's script to patch your MBR. This patch is absolutely necessary for every Windows. Pay particular attention to patch the right disk!!! If you patch an OS X disk that holds no Windows you are in serious trouble. The wrong disk selection will screw up your disk count and nothing will work right from there. In OS X open the terminal utility. Type "sudo" and a blank. Then drag the unzipped script shell file into the terminal with your mouse. Input your admin password and follow the dialogue. For this you will need the disk codes that you have noted on paper. The program tries to find your Windows disk but you have to make sure it finds the right one. It often suggests a wrong disk. Be really carefull to insert the complete name for the disk!! In our example it was /dev/disk2 for the second disk. Just inserting the number like 2, 0 or 3 or disk3 or disk4 will not work. When you are done with patching your MBR the program will confirm to you that you were successfull. You shut down OS X and restart Windows. If you have done the patch right and selected the right controller for your chipset Windows should now show SATA drives and get busy to find the real AHCI drivers for them. If you installed MS AHCI 1.0 you can now switch to the Intel driver without problems. If you got it wrong Windows will malfunction with a BSD on loading. You can use special load options to go back to the last known good configuration which you hopefully established by setting the restore point or you can restore Windows by Winclone. Start all over with the registry edit until you got it right. 5.4 Installing the Intel Matrix Storage Manager To load the Intel Matrix storage driver you can now execute the Intel executable package which we downloaded. It will be accepted by your machine. If you try installing that package before the patch it will tell you that you are loading a wrong package for your machine. Restart Windows after the storage driver has completely installed. In Vista and Win7 you have to run the executable as administrator. Now you should be all set. 6. Trouble shooting What to do if you patch the wrong drive? I happened to patch my OS X drive which was partitioned in three partitions of which one was NTFS. So the patch program thought I had a Windows on it. I did not check it and so I went ahead and patched it. It turned out to be real bad news because now as long as this drive is in the system I get BSD and the patch method does not work any more. I went back to the thread at Insanelymac and Johnsock had left instruction how to recover the backup MBR. It is stored in USERS/Yourname/backup.mbr Johnsock advised to run in terminal: sudo fdisk -y -u -f ./path/to/backup.mbr /dev/rdisk0 But that command is designed for drives with one partition I guess. So I modified my command to: sudo fdisk -y -u -f /Users/gugucom/backup.mbr /dev/rdisk0 That command worked for me. Feel free to challenge everything I have written here. I have only limited experience and will like to discuss any questions you have as good as I can. I tought the issue deserves its own thread so that we can collect the wisdom of all users here.