It isn't the first time that AMD or its partners "unintentionally" mixed up the specs of some card so this really doesn't come as a surprise. AMD and its partners might change this on its next batch so don't get you hopes up unless you already snatched a HD 6790 that has 24 ROPs. We still don't know how these cards ended up with extra ROPs but we guess that more info should surface pretty soon and AMD might have a thing or two to say about this situation.
Credits go to Techpowerup for this one as their GPU-Z was the first clue to find out the 24 ROP info. You can check out more here.
