It's a Sapphire 7970 Vapor-X so it weighs a decent amount. It's mounted correctly but the thing is that a lot of graphics cards (including this one) sag down due to the only thing holding it up is the board. The HAF X has a thing which you can put it in to hold up a graphics card to prevent it from being out of place, which would help sagging. The thing is that I don't know if it's worth it since I'm not sure if sagging is bad. Any ideas?
What do you mean the only thing holding it up is the board? It should be attached at the back of the computer with 2 screws, or latches, depending on the type of case you have, that holds it securely in place, and would not allow it to sag.