I’ve not seen non-flashed cards running at half speed, and I’ve run lots of non-flashed cards. CUDA has direct memory access and isn’t limited by driver issues related to OpenGL or OpenCL.
This is covered in the manual. It’s called conforming. You export XML from FCP bring that into resolve, tell it to link to the original camera files (ie DNG).
In resolve 9, davinci added a disk based database as an option instead of the Postgres database that’s usually used. I believe it’s now the default in the lite version.
You can get them pretty high by lifting the clip… there are two controls on the soft clips… clipping and softness. Raise the clip level and you can get a rather high amount of lift.