Mar 17, 2018 Re: Modified RockHopper2 ATI drivers for Mac Mini( OS 9 ). « Reply #21 on: March 17, 2018, 09:44:58 PM » interesting, my PowerBook6,5 has never had such an issue.
Ati Drivers Windows 10
Someone asked me about this, so I decided I ought to make a guide about it. On the Internet, you may find a guide someone wrote at the beginning of December (2015) for hacking the updated Radeon drivers onto one's Mac (see References section below). It's something that's been going on since at least the 2011 AMD MacBook days, though newer versions of Windows have made such guides obsolete.
For the lazy, you can download the M370X driver file from here: http://echo.jatsby.com/m370x-december2015.zip (I haven't actually tested this, as I don't have a Bootcamp Windows partition atm, let me know if it works)
Here's how I updated my MacBook's M370X drivers:
Download the latest beta or release Crimson driver from http://support.amd.com/en-us/download. At the time of this writing, the beta and release versions of Crimson were the same (?). Go ahead and get the whole software package rather than just the display driver.
Run the .exe, which will extract the drivers and software to C:/AMD/. It will complain about not finding compatible products, ignore it and head to that folder in C:/AMD/. Actually, in the very latest Crimson driver software package, it doesn't complain right away, so just close the installer ASAP once the files have been extracted.
Navigate to C:/AMD/'whatever version of Crimson you downloaded'/Packages/Drivers/Display/WT6A_INF/ and if you have the very latest Crimson driver, it will only have one 'C0...'.exe/.inf/.cat set. In the past, Crimson drivers have come with 3 or so sets of files that start with 'C0', making it a little difficult to determine which one to use.
Open the Setup Information (.inf) file in your favorite text editor (mine's Notepad lol) and Ctrl+F for 'ExcludeID=PCIVEN_1002&DEV_6821&SUBSYS_0149106B'. Find it, and delete it. This line, as you can probably guess, blacklists the M370X, a.k.a 1002:6821 as far as Windows is concerned. Save the file and close it.
If you're on Windows 8 or above, you'll have to use Advanced Startup to disable Driver Signature Enforcement. Head to Settings (not Control Panel), you know that app version of Control Panel, Update and Security -> Recovery -> Advanced startup. Windows should reboot into the recovery menu. Then I believe it's 'Advanced Options' -> 'Startup Settings' -> 'Disable Driver Signature Enforcement'.
Okay now back in Windows, go to Device Manager and right click on the M370X -> 'Update Driver Software' -> 'Browse my computer...' -> 'Let me pick...' -> 'Have Disk' -> and navigate to the WT6A_INF (make sure it's not in .zip form, extract it if you got it from the link above).
It's not signed, but install it anyway! That should do it.
References
Notes
It should be possible to install the Crimson software suite by mixing with files from the official bootcamp drivers. I did it once, I forget exactly how, but I'll look into it again.
I don't know what improvements, if any, you'll see in games, though it should be comparable to improvements we've seen with other AMD GPUs running Crimson. For example, Fallout 4 framerates should theoretically improve by about 10FPS at 1080p, and up to 20FPS at 1440p+ resolutions, not that the M370X can handle it, but maybe you've adapted this guide to work with your M390 on your iMac or what have you...
Yeah so this guide should work with all the other Mac/AMD GPU combinations out there, so long as you edit the correct .inf file (remember, there could be as many as three in the WT6A_INF file).
Comment below with your FPS improvements!
EDIT 1/10/16: The pre-made driver above is for Windows 10 only. Windows 8.1 users, I suggest creating the modded driver file yourself (it only takes a minute!). I plan on updating this post with links for premade drivers for both versions of Windows for Crimson 16.1, but at the moment the 16.1 drivers do not include any updates for the M370X. The latest version for the M370X is 15.300.1025.1001, dated 12/4/15 (that's what's above at echo.jatsby.com). The latest official Bootcamp driver is still 9/21/15 (15.200.xxx).