We've discussed iGPU vs dGPU, we've also discussed the possibility of a 15W CPU in the 13" but what about a 28W CPU in the 15"? I've been thinking a lot about this lately. Apple would be able to make very thin MacBooks by using 28W CPU:s instead of the current 47W.
If we assume that the next 15" will drop the dGPU option (just an assumption), then the 28W vs 45W is basically a dual-core + HD550 vs quad-core + HD580. For GPU performance, the HD580 is going to outperform the HD550 but what exactly is the practical benefit of a quad-core CPU? Of course multi-threaded applications will be able to take advantage of the quad-core but what kind of applications are these? AFAIK quad-cores will not matter for video editing, photo editing or 3D rendering because these can be done a lot faster and more efficient using the iGPU. I doubt even games can benefit a lot from quad-cores because the GPU will be the limiting factor and benchmarks have shown that GPU:s are more important than CPU:s when it comes to gaming. Even web browsing isn't much faster on the quad-cores because internet speed is the limiting factor most of the time.
My point is that most MBP buyers will rather have a very thin and light 15" MBP with very long battery life than a thicker and heavier MBP with a quad-core CPU that is rarely beneficial and with a faster iGPU. I personally would like to have a thin and light 15" MBP but I would rather have at least the HD580 iGPU. I know it would be really bad for the power users if Apple decided to drop both the dGPU and quad-cores from their most powerful laptop but I just wanted to share my thoughts with you guys.
I've seen a lot of people here wanting the 13" MBP to have a quad-core CPU, what are your reasons / use cases?