The 970 is the only card with that issue, and the 0.5GB of RAM isn't "faulty" it's just really slow. The 980 is fine. You don't need to care about bottlenecking, but your CPU will be the slowest part in the build I'd imaging in a lot of games. Not anything to worry about though, something has to be the slowest. Yes, the 980 will "handle" every title in 1080p on ultra, but that doesn't mean you'll always be getting 60fps+.