Thats a normal behavior...it is for sure not a not a Revit software Glitch or Problem as much as it is NOT a windows problem because its not windows which controls the 3rd party Graphic Card behavior it the the Graphic Card driver.
First you need to know that Autodesk does have a list of Recommended/Supported/Not supported Grafic Cards which you might first wanna check before you take any furtheraction...and this list works by (Manufacturer>Product>Model>Operating System VS. each Autodesk Product and it might vary with the different Autodesk software you intend to use (ie: the difference between AutoCAD and Revit using different Graphic hardware...You can check HERE which cards are supported for each software and which are not.
Suggested solution:
You need to check if your Graphic Card has something similar to the NVidia Optimus technology...What OT basically does is switchs between two graphics adapters within a computer system in order to provide either maximum performance or minimum power draw from the system's graphics rendering hardware...This switching depends mainly on the resource load generated by the software applications.
If AMD has a similar tech; its driver should allow you to force the use of the NVidia graphics card when using Autodesk software. In the NVidia fit gives the option to select "Autodesk Composite" to change the graphics processor for all Autodesk software under "Select a program to customize" OR the option to select the specific Autodesk Program from the drop down list. SEE VIDEO
