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macrumors newbie
Original poster
May 13, 2021
Hi there! I have a problem with my iMac mid 2011. I just replace my old HDD with a SSD. In Mac OS, everything's fine, max sata3 speed (about 500Mb/s read and 4xxMb/s write. But in bootcamp with W7 installed, its running with sata 2 speed (2xxMb/s read&wirte, SATA controller in Devices Manager). Is this my mac's limit? Can I resolve this?


macrumors newbie
Oct 6, 2023
I have the exact same issue. Is this a driver issue? Does anyone know how to solve it?

Here are two tests:

MacOS Ventura

macOS Ventura - 2023.10.05.png

Windows 10

Windows 10 - 2023.10.05.png


macrumors newbie
Oct 6, 2023
I fixed!


These are the steps I followed:

PART ONE - Apply AHCI patch
  1. Backup all your data.
  2. Download this AHCI enabler package (contains BOOTICEx64.exe and patchedcode.bin)
  3. Run BOOTICEx64.exe as admin.
  4. On "Pysical Disk" tab, make sure your destination disk is your desired drive.
  5. Click on Process MBR.
  6. Select Windows NT 5x/6x MBR.
  7. Click on Restore MBR.
  8. Select the patchedcode.bin file.
  9. Make sure "Keep signature and partition table untouched" is marked.
  10. Click on restore.

PART TWO - Enable AHCI using Registry Editor
  1. Now open Windows Registry Editor.
  2. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStorV and edit Start DWORD to 0.
  3. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iaStorAVC\StartOverride and edit 0 DWORD to 0. (This value will return back to 3 after you restart the computer later.)
  4. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\storahci and edit Start DWORD to 0.
  5. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\storahci\StartOverride and edit 0 DWORD to 0.
  6. Close regedit, reboot your system and you are done.

I want to credit this solution to @sanke1 and Shawn Brink from Windows Ten Froums.

Good luck!
Last edited:
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