Just got Lightroom 6!! Finally they are using the GPU to make things faster. Just one problem, its using my crappy Intel 4600 GPU instead of the NVidia Quadro K1100M in my dual GPU Notebook.
Adobes own advise from their FAQ is to disable the Intel Card. I tried that, all it did is screw up almost everything on the PC. Thanks Adobe for that… So looking around the interwebs I found way too many people having this issue but none having a good solution.
After about 3 hours of messing around with ProcessMon.exe I discovered it was trying to write to c:\ProgramData\NVidia Corporation\Drs folder. Only problem is that folder did not exist.
Simply create the folder, and give “everyone” full control in the security Tab and you should be good to go.
One thing to note, it seemed like it took two saves to start working for me, not sure what that was about but finally I was able to use the “Managed 3D Settings” part of the NVidia Control Panel to set Lightroom.exe to use the NVidia GPU.
Hope it helps you!