Category Archives: Windows

Fixing the AMD AHCI drivers for SB7xx on Windows 7

I heard a lot of urban legends about the Windows Update service that messes up your machine. Of course, I dismissed all of them with the classic “worksforme” as didn’t happen to me. Until Microsoft delivered a 3rd party driver update via an optional package. You know, like the stuff that comes from the vendor and it isn’t properly tested. I had the lack of inspiration to check that too instead of simply ignoring it, like I usually do with Bing Desktop and Silverlight. The next thing was a BSOD at boot.

Had to disable the AHCI in BIOS and revert to using IDE mode for the SATA ports. Which kinda sucks for some reasons. The most important: the SSD performance is hurt under IDE mode, the TRIM command won’t work under IDE mode without 3rd party software since only the MSAHCI driver implements TRIM from Windows 7, and the fact that my HDD array doesn’t support NCQ under IDE mode.

When it comes to drivers, AMD is still a shitty company. Even more, their engineers didn’t grasp the concept of backward compatibility. Uninstalling the driver that broke my installation and installing a driver that works proved to be a non-trivial task. Fortunately I found this post on pchelpforum.com.

For the sake of avoiding the link rot, I’m going to reproduce the essentials for posterity, with the same disclaimer as the original – you’re on your own if you mess up your machine and I’m not taking any responsibility if you follow these:

  • Delete any older version of the amd_ahci driver from here: C:\Windows\System32\DriverStore\FileRepository. The folders with older AMD AHCI drivers are named something like: amd_sata.inf_amd64_neutral_c85cc6046149a413 (i386 on 32-bit and most probably another hash). In order to remove the directory, you need to either elevate your explorer / shell to SYSTEM privileges, or take the ownership of the driver directory, add proper permissions, then delete it.
  • From HKLM/SYSTEM/CurrentControlSet/services delete amd_sata and amd_xsata. There’s no need to remove the entries without the underscore (amdsata and amdxsata).
  • Reboot the computer. Don’t change from IDE to AHCI. The driver that actually worked for my combination, which is AMD 780G / SB700 is this one. Execute the installer, wait till it finishes to copy the files to C:\ATI\Support, then cancel the setup when the Catalyst installer starts.
  • Open the Device Manager. Action » Add legacy hardware » Advanced mode » Show All Devices » Have Disk. Browse the extraction path for the above package: C:\ATI\Support\11-12_vista32-64_ahci\Packages\Drivers\SBDrv\SB7xx\AHCI. There’s a couple of directories: LH – for 32-bit and LH64A – for 64-bit. Select “AMD SATA Controller” then continue. Unlike the author of the original material, I didn’t get an error about the device not starting.
  • Reboot the computer. Don’t change from IDE to AHCI. Go to Device Manager. Under IDE ATA/ATAPI controllers should be at least an entry with a yellow exclamation mark, AMD SATA Controller. Uninstall “AMD SATA Controller” without checking “Delete the driver software for this device”. Reboot the machine.
  • Go to BIOS, enable AHCI. After boot, the OS installs the proper drivers, then prompts for another reboot. Reboot the machine. Done.

In my case, it simply fixed the driver installation from the failed Windows update as the driver that runs on my machine is from 2013 and the driver used in the above steps is from 2011. The drivers from the latest Catalyst, 13.4 failed to install via the “Add legacy hardware” method or via a standard Catalyst setup.

amd-sata-controller

Some benchmarks with a SSD drive under IDE mode:

benchmark1-idebenchmark2-ide

And some benchmarks under AHCI mode:

benchmark1-ahcibenchmark2-ahci

I guess the sharp drop was due to TRIM doing its job. Yes, it’s enabled:

trim