How to update 27" iMac ( 2010 ) on Windows:
Apple and Windows Drivers, it just don't matches. AMD sells many more GPU's thanks to Apple, but when it comes to iMac driver support, it's seems that it's not that important for AMD.
You've probably noticed by know that by default, you get the ATI 10.4 driver.
Since Apple is using so called "custom" cards in certain iMacs ( example: the 5750 in the 2010 iMac is a 5850 Mobility Radeon ) it's not always easy to install the latest update.
Follow these simple steps:
1. Uninstall the current ATI bootcamp driver completely and reboot your iMac.
2. Download and install the latest "notebook graphics" driver:
http://support.amd.com/us/gpudownload/Pages/index.aspx
ATTENTION: If you're upgrading from 11.x to 11.6, skip step 1!
This small driver update from 10.4 to 11.6 will add the following improvements:
- GPU acceleration of H.264 video content using Adobe Flash Player 10.1 ( or higher )
- Video De-blocking support ( Reduces blocking artifacts seen in low-bit rate video during playback )
- Mosquito noise reduction ( Reduces mosquito noise seen in highly compressed progressive video, during playback )
- Official support for OpenGL 4.0 and OpenGL 3.3
- Support for OpenGL 4.1
- OpenGL ES 2.0 support
- Enhanced Pull-down detection
- ATI Radeon GPU acceleration of VLC 1.1.1 ( or higher ) Media Player
- Video accleration for HD WMV video content
- Enahnced Dynamic Contrast video controls
- Enhanced Video Quality default options
- Catalyst AI Texture Filtering updates
- Tessellation Controls
- Morphological Anti-Aliasing support
- Stereo 3D gaming support
- Performance increase in 3DMark11/Vantage and many games!
- A lot more Catalyst™ Application Profiles
- Many bugfixes/resolved stability issues and enhancements for Windows 7!
- And a lote more I probably forgot to mention...