Hrm, I have been shying away from updates for a while; With 10.10.4 released, then a security update, what would happen were I to run the app store update as usual? Black screen, or stock driver support?
I think I'm on 10.10.2 with those Web drivers. MacPro 5,1, GTX650Ti
It's my understanding that Native Apple Drivers support your card, so you should have no issues updating your OS and Web Driver.
Lou