Did you grab and install the graphic driver from Nvidia?
Apple or even Microsoft driver are not always the best.
Boot Camp 5.0 drivers to start just to enable the various chipsets and basic support.
I see a black screen or distortion when I install Windows 8 on a MacBook Pro (Retina, 13-inch, Late 2012). How do I fix this?
The Windows 8 installer does not contain the correct graphics driver for your computer. You'll need to attach the USB media that contains the Boot Camp drivers during installation to address this issue. See this article for more information.
Windows 8, Thunderbolt devices are being recognized when I connect in. How do I fix this?
Disable the Windows 8 Fast Boot feature to allow Thunderbolt devices to be recognized. See Boot Camp: Thunderbolt devices not recognized after Windows 8 upgrade for instructions.
Also with any GTX you may want to see if there is a CUDA driver as well.
- Intel HD Graphics 4000
- NVIDIA GeForce GT 650M with 1GB of GDDR5 memory and automatic graphics switching
- Dual display and video mirroring: Simultaneously supports full native resolution on the built-in display and up to 2560 by 1600 pixels on up to two external displays, at millions of colors
Also, Intel 4000 graphic driver, switching between Intel HD and Nvidia has been a problem.
From my (now old) notes:
I had problems with windows 7 after the installation using boot camp. The GT 650M was not showing up as the graphics adapter. I fixed the problem by inserting my windows support software CD a second time. I did not let it use auto run. I went into the Windows 7 directory and then into the Nvidia directory and ran setup.exe. This installed the Nvidia drivers for me. If this works correctly, you will have an Nvidia control panel available to you. I set the resolution to 2880x1800. I also set windows to 200% magnification.
I think what happens is that after you install windows, and then run the windows support CD, the main boot camp setup script seems to stop on the nvidia driver install--everything else installed correctly.
The 2012 MacBook Air suffers from an EFI firmware bug that under Windows blocks turbo mode.
Disable Windows 8’s Adaptive Brightness to Fix Dark Screen Problems2012 MacBook Air plagued by audio noise with Apple's Thunderbolt display
Intel Windows 8 Graphic Driver
Intel Download Center: http://downloadcenter.intel.com/
3rd Generation Intel HD Graphics 4000 Windows 8 64-bit
Well, I did download and install the Nvidia drivers directly from their website back then. I also installed all the Boot Camp drivers from my pen drive.
It's odd, because even if not for the Photoshop problems, some pieces of graphics I've made, namely avatars, still don't look as sharp as they do on a regular Windows computer.