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sanke1

macrumors 65816
Original poster
Nov 9, 2010
1,067
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By request, I am writing a tutorial to enable AHCI mode for iMacs which run Windows in IDE mode (via Bootcamp partitioning)

I am using 21" iMac mid 2011 model. I installed Samsung 840 Evo SSD. But SSD benchmarks in Windows gave 30-40% lower than the rated performance. So on a bit of googling, I found out that Apple does not let our third party SSDs (or even our spinning hard disks) to run at full speed in SATA AHCI mode. Instead, we are stuck in SATA IDE mode which is slower and does not support Windows native TRIM and NCQ commands.

Warning: I am not responsible for data loss or damaged hard drives. This method does not work for 2009 and 2010 iMac and MBP models running on Nvidia nForce chipset.

At this moment, use it for 2011 models only.

Any other models like Mac Pro, try at your own risk.


As a standard practice, backup all your data. Or do this on a fresh Windows Install.

Go to device manager and under IDE ATA/ATAPI controllers check if it is showing the controller running in IDE mode like this

or7Htq5.png


If the entry is similar like above with no mention of AHCI then you are good to go with the following tutorial.

Newer Macs already run in AHCI mode so this tutorial need not apply.

So... your SSD or Hard drive is running in IDE mode,

Download this AHCI enabler package by clicking here.
Extract it to a folder.

1. Open BOOTICEx64.exe from the BOOTICEx64_v1.321 folder. (Right click and Run as Administrator)

Click as per shown in the pics.

sdEbsDT.png


Make sure the boot drive containing Windows is selected. We mistakenly select PEN drives or any other drives and wonder what went wrong.


dV2FpBx.png

It would make great sense if you click on Backup MBR first and store a copy. You can use this file to restore things back to normal if things go wrong. Restore using the same tool or through Windows recovery commandline tools.

Dont worry. My MBR has already been modified hence it is showing Unknown MBR. Your's will show NT6 or similar.

D6TN87v.png


Here we point out the modified MBR file which enables AHCI support from boot.

Aw8xYbY.png


Select the correct file patchedcode.bin and click on Open.

aR72WWO.png


Click Restore and make sure settings are as per the above screenshot.

You should be greeted by success message. If not then you did not follow the arrows or run the program as administrator.

2. Go to device manager and uninstall the IDE controller. (Name of the IDE controller will vary slightly based on your iMac or MBP model) It will ask you to reboot Windows for changes to take effect. But we are not going to reboot Windows yet.

3. There is a reg file called AHCI.Detection.Reset (Inside AHCI Mode Enabler folder)
Double click on it and import it into Windows registry.

Now Reboot Windows.

Once you log into Windows, go to device manager and see what has been detected under IDE ATA/ATAPI controllers. (Again, this tutorial will not work for 2009 and 2010 iMac and MBP models running Nvidia nForce Chipset)

If it says Standard SATA ACHI Controller, congratulations, you have successfully enabled AHCI mode.
Install Intel AHCI drivers which are in the same earlier downloaded folder to get further 5% SSD performance boost.

This is an extremely easy process to do with intermediate computer knowledge. Running SSD in AHCI mode will reduce wear and tear and increase it's life also making it faster.

The only downside is you will have to disable sleep and hibernation under Windows Power Options.

A small mini tutorial for that:

1. I found out that sleep needs to be disabled in Windows 7, 8 and 10. For Windows 8 and 10, Right click on Start button and go to power options. Balanced profile should be selected by default. Click on Change plan settings.
Put the computer to sleep -> Never

2. Again Right click on Start button and go to power options. Click Choose what the power buttons do. Then click Change the settings that are currently unavailable.
When I press the sleep button -> Do nothing
Then under Shutdown settings at the bottom, untick Sleep and Hibernate

Only these settings need to be changed and no other. In Windows 7, search for power options.

2. MAC Fan Control software needs to be installed to control the out-of-control fans. In the app, set the hard drive's fan speed to sensor based value.

Download Mac Fan Control from here Dirtect Link


Enjoy.
 
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Super powerful tutorial.

This does not apply for me because mine is early 2014 MacBook Air.

However, I still want to thank for your great effort to break Apple in purpose limitation and unleash full power of an SSD.

I wonder, if this method is stable enough not going something wrong in long term?
 
Super powerful tutorial.

This does not apply for me because mine is early 2014 MacBook Air.

However, I still want to thank for your great effort to break Apple in purpose limitation and unleash full power of an SSD.

I wonder, if this method is stable enough not going something wrong in long term?
Been using this method since 3 years. This is solid and survives all Windows Updates as we are not touching any Windows file.
 
Or you could just install Windows in EFI mode. However there isn't much speed difference with all these tricks over the default Boot Camp install.

The IDE mode you are seeing is fake, it's a software version that translates IDE to AHCI calls - the SSD itself is running as it normally would except there is a little overhead for the translation. Trim functions normally (you can check this in Samsung Magician or the Command Prompt) and benchmarking with CrystalDiskMark shows that your SSD is running at around the speed it should (minus that little 10-15% overhead which makes very little difference in real world use).
 
Or you could just install Windows in EFI mode. However there isn't much speed difference with all these tricks over the default Boot Camp install.

The IDE mode you are seeing is fake, it's a software version that translates IDE to AHCI calls - the SSD itself is running as it normally would except there is a little overhead for the translation. Trim functions normally (you can check this in Samsung Magician or the Command Prompt) and benchmarking with CrystalDiskMark shows that your SSD is running at around the speed it should (minus that little 10-15% overhead which makes very little difference in real world use).
Actually if 2011 iMac is run under efi mode, I cannot install drivers for Amd Radeon 6700 series and Cirrus Audio. This method enables the true AHCI mode.

TRIM and NCQ simply don't function under IDE mode.
 
Actually if 2011 iMac is run under efi mode, I cannot install drivers for Amd Radeon 6700 series and Cirrus Audio. This method enables the true AHCI mode.

TRIM and NCQ simply don't function under IDE mode.

If that iMac can't run EFI mode and you think you need a hack just to get 25MB/s improvement on large writes then feel free to do so.

I don't know about NCQ but Trim does function and my Mac is older than yours. See below... 'Zero' means Trim is enabled and functioning.
 

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Thank you for this! Worked perfectly on my Early 2011 15" Macbook Pro. I recently put in a Samsung 850 SSD. The provided magician software was claiming I was in IDE mode, and could not detect the SATA controller. After using your method here, I'm all good with AHCI on my Bootcamp partition. You rock!
 
The increase in speed is about 2x works great (before 350Mb/s now 560Mb/s write speed), but I can not use sleep mode. I am using MBP early 2011 with windows 10 and samsung pro SSD.
Is there reversed process to undo the changes and go back to IDE or how can I enable the sleep setting when I close the lid?
Now I have error critical_process_died when the windows tries to wake up from sleep mode.
Thank you.
 
Last edited:
By request, I am writing a tutorial to enable AHCI mode for iMacs which run Windows in IDE mode (via Bootcamp partitioning)

I am using 21" iMac mid 2011 model. I installed Samsung 840 Evo SSD. But SSD benchmarks in Windows gave 30-40% lower than the rated performance. So on a bit of googling, I found out that Apple does not let our third party SSDs (or even our spinning hard disks) to run at full speed in SATA AHCI mode. Instead, we are stuck in SATA IDE mode which is slower and does not support Windows native TRIM and NCQ commands.

Warning: I am not responsible for data loss or damaged hard drives. This method does not work for 2009 and 2010 iMac and MBP models running on Nvidia nForce chipset.

As a standard practice, backup all your data. Or do this on a fresh Windows Install.

Go to device manager and under IDE ATA/ATAPI controllers check if it is showing the controller running in IDE mode like this

or7Htq5.png


If the entry is similar like above with no mention of AHCI then you are good to go with the following tutorial.

Newer Macs already run in AHCI mode so this tutorial need not apply.

So... your SSD or Hard drive is running in IDE mode,

1. Download this AHCI enabler package by clicking here.
Extract it to a folder.

Go to device manager and uninstall the IDE controller. (Name of the IDE controller will vary slightly based on your iMac or MBP model) It will ask you to reboot Windows for changes to take effect. But we are not going to reboot Windows yet.

2. There is a reg file called AHCI.Detection.Reset (Inside AHCI Mode Enabler folder)
Double click on it and import it into Windows registry.

3. Open BOOTICEx64.exe from the BOOTICEx64_v1.321 folder. (Right click and Run as Administrator)

Click as per shown in the pics.

sdEbsDT.png


Make sure the boot drive containing Windows is selected. We mistakenly select PEN drives or any other drives and wonder what went wrong.


dV2FpBx.png


Dont worry. My MBR has already been modified hence it is showing Unknown MBR. Your's will show NT6 or similar.

D6TN87v.png


Here we point out the modified MBR file which enables AHCI support from boot.

Aw8xYbY.png


Select the correct file patchedcode.bin and click on Open.

aR72WWO.png


Click Restore and make sure settings are as per the above screenshot.

You should be greeted by success message. If not then you did not follow the arrows or run the program as administrator.

Now Reboot Windows.

Once you log into Windows, go to device manager and see what has been detected under IDE ATA/ATAPI controllers. (Again, this tutorial will not work for 2009 and 2010 iMac and MBP models running Nvidia nForce Chipset)

If it says Standard SATA ACHI Controller, congratulations, you have successfully enabled AHCI mode.
Install Intel AHCI drivers which are in the same earlier downloaded folder to get further 5% SSD performance boost.

This is an extremely easy process to do with intermediate computer knowledge. Running SSD in AHCI mode will reduce wear and tear and increase it's life also making it faster.

The only downside is you will have to disable sleep and hibernation under Windows Power Options. Also disable sleep under Power button actions. When you press power button, it must shutdown. When you press sleep button, it must do nothing. If you close the screen lid, it should shutdown as well.

But performance increase is totally worth it.

Always shutdown your iMac or MBP instead of putting it to sleep if you have enabled AHCI mode. It is just the nature of Apple's firmware implementation preventing sleep mode.

If your iMac fans are loud due to 3rd party SSD, install MAC fan control and set hard disk fan to SSD sensor based value.
Enjoy.

It may be worth to add to backup the MBR using BOOTICE in advance of the patch. This will allow users to switch back to IDE mode in case they want for some reason.
 
To go back to IDE mode,

1. Uninstall SATA AHCI controller device from device manager.
2. Boot into Windows setup preinstallation environment using bootable DVD or USB.
3. Choose Repair option at the start.
4. You have to start Commandline from one of those Advanced Troubleshooting options and type this: bootrec /fixmbr
5. Exit commandline and reboot.

More detailed info here

Just don't forget to uninstall SATA AHCI controller driver from device manager before fixing mbr.
 
Thanks for writing this. I have an Early 2011 MBP with an Intel Chipset. I was following this, but for some reason the Destination Disk dropdown in BOOTICE is blank. I have an EVO 850 installed. Any idea why that list would be blank?
 
Thanks for writing this. I have an Early 2011 MBP with an Intel Chipset. I was following this, but for some reason the Destination Disk dropdown in BOOTICE is blank. I have an EVO 850 installed. Any idea why that list would be blank?

Reboot your MBP.
Follow the steps in the updated tutorial step by step.
 
Last edited:
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Hi! I was wondering how much of a speed increase I can expect on an early 2011 MBP with a Samsung 850 SSD enabling the UEFI. I'm kinda scared of disabling sleep mode, but I'll do it if it's worth it!
 
Hi! I was wondering how much of a speed increase I can expect on an early 2011 MBP with a Samsung 850 SSD enabling the UEFI. I'm kinda scared of disabling sleep mode, but I'll do it if it's worth it!

If you want UEFI you need to install windows again in this mode. Its worth it is much faster but you will not have audio.

If you apply the patch from this site you will have no other option but to disable the sleep mode. Its worth it is fast. But you will miss the sleep mode also :).

I have mbp 2011. I was not able to find solution for it that I am fully satisfied so I am in IDE mode now.
 
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hi, i was trying the method you provide. my laptop is the mbp 2011 early, and i install the win10 in my second ssd which also contain the ei captain os. my second ssd was installed at the cd-rom port. i operate your step on win10, but after rebooting, it still remain IDE mode. do you have any idea what's wrong?
 
I would like to point out that people use this tweak wisely and only after they have backed up their MBR. My experience with my MacPro 1.1 is that speeds are the same, I have lost sleep function and despite the fact that i have followed the above mentioned procedure for reverting changes to IDE, I still cannot make sleep working.
For anybody interested in reverting back to IDE and make sleep working again, please see this thread where I have requested and I am awaiting for a solution ---> https://forums.macrumors.com/thread...ce-to-enable-ahci-mode-in-windows-10.1911036/
 
Last edited:
By request, I am writing a tutorial to enable AHCI mode for iMacs which run Windows in IDE mode (via Bootcamp partitioning)

I am using 21" iMac mid 2011 model. I installed Samsung 840 Evo SSD. But SSD benchmarks in Windows gave 30-40% lower than the rated performance. So on a bit of googling, I found out that Apple does not let our third party SSDs (or even our spinning hard disks) to run at full speed in SATA AHCI mode. Instead, we are stuck in SATA IDE mode which is slower and does not support Windows native TRIM and NCQ commands.

Warning: I am not responsible for data loss or damaged hard drives. This method does not work for 2009 and 2010 iMac and MBP models running on Nvidia nForce chipset.

As a standard practice, backup all your data. Or do this on a fresh Windows Install.

Go to device manager and under IDE ATA/ATAPI controllers check if it is showing the controller running in IDE mode like this

or7Htq5.png


If the entry is similar like above with no mention of AHCI then you are good to go with the following tutorial.

Newer Macs already run in AHCI mode so this tutorial need not apply.

So... your SSD or Hard drive is running in IDE mode,

Download this AHCI enabler package by clicking here.
Extract it to a folder.

1. Open BOOTICEx64.exe from the BOOTICEx64_v1.321 folder. (Right click and Run as Administrator)

Click as per shown in the pics.

sdEbsDT.png


Make sure the boot drive containing Windows is selected. We mistakenly select PEN drives or any other drives and wonder what went wrong.


dV2FpBx.png


Dont worry. My MBR has already been modified hence it is showing Unknown MBR. Your's will show NT6 or similar.

D6TN87v.png


Here we point out the modified MBR file which enables AHCI support from boot.

Aw8xYbY.png


Select the correct file patchedcode.bin and click on Open.

aR72WWO.png


Click Restore and make sure settings are as per the above screenshot.

You should be greeted by success message. If not then you did not follow the arrows or run the program as administrator.

2. Go to device manager and uninstall the IDE controller. (Name of the IDE controller will vary slightly based on your iMac or MBP model) It will ask you to reboot Windows for changes to take effect. But we are not going to reboot Windows yet.

3. There is a reg file called AHCI.Detection.Reset (Inside AHCI Mode Enabler folder)
Double click on it and import it into Windows registry.

Now Reboot Windows.

Once you log into Windows, go to device manager and see what has been detected under IDE ATA/ATAPI controllers. (Again, this tutorial will not work for 2009 and 2010 iMac and MBP models running Nvidia nForce Chipset)

If it says Standard SATA ACHI Controller, congratulations, you have successfully enabled AHCI mode.
Install Intel AHCI drivers which are in the same earlier downloaded folder to get further 5% SSD performance boost.

This is an extremely easy process to do with intermediate computer knowledge. Running SSD in AHCI mode will reduce wear and tear and increase it's life also making it faster.

The only downside is you will have to disable sleep and hibernation under Windows Power Options. Also disable sleep under Power button actions. When you press power button, it must shutdown. When you press sleep button, it must do nothing. If you close the screen lid, it should shutdown as well.

But performance increase is totally worth it.

Always shutdown your iMac or MBP instead of putting it to sleep if you have enabled AHCI mode. It is just the nature of Apple's firmware implementation preventing sleep mode.

If your iMac fans are loud due to 3rd party SSD, install MAC fan control and set hard disk fan to SSD sensor based value.
Enjoy.
 
Hello guys
I just did this, but to a PC!!!!!! I didnt realize that this was about an iMac before it was too late. What can I do now to repair the registry? Please please
Greetings
Brian
 
Hello guys
I just did this, but to a PC!!!!!! I didnt realize that this was about an iMac before it was too late. What can I do now to repair the registry? Please please
Greetings
Brian
Read my post #13
 
Yes sucks. This is in Windows on Mac section so it is assumed that everyone replying is running Windows on a Mackintosh hardware.
 
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