Unified Ram, Huma tech, is as efficient as you can get for the setup. There is not split memory pool that you have to program for like the PS3. As well as no helper ram module like ESRAM that you have to program for with the Xb1.
That is a powerful set up and is the way most systems are being set up these days. Though I'm not sure what it has to do with the efficient use of the silicon in the system. I think it has more to do with efficient use of dev time.