Does your card have the passive control feature which shuts off the fans ... MSI introduced in 2008, Asus and others started using with 9xx series.
I have never been inclined to use AB's fan curves as I find the provided curves acceptable on air cooled builds but my own boxes use water in which case use the MoBo Utility. If the GPU provides fan shut off on it's own already built in, trying to over rule that may be problematic.