According to these rumors, Orbis is basically an APU + GPU design, but integrated into a single SoC instead of a MCM or SiP, which allows for minimum latency and maximum bandwith at the same time.
On the APU side we have the eight Jaguars combined with 256 GCN shaders, together burning an incredible amount of 512 GFLOPS! Just for the record: An Intel Core i7 4770k desktop CPU (only) delivers 448 GFLOPS. Imagine what this could mean for AI, animations, physics, etc. On the GPU side we have a processor that is basically a small HD7850 Pitcairn. In my eyes this GPU is strong enough to deliver enjoyable graphics for a next gen gaming console, especially when keeping the perverse TDP of modern high end cards in mind. We're most likely talking about 3rd gen HSA for Orbis, which means a unified adress space for CPU and GPU(s), pageable system memory for the GPU(s) with CPU pointers, and a fully coherent memory between CPU and GPU(s). Simply put, no copy work between the CPU and the two iGPs. This will be a hell of a speedup compared to a modularly designed PC (take a look at the superb 28nm Temash SoC rendering Dirt: Showdown at 1920x1080 with 5W!!!)
The reasons for going with APU + GPU are better programmability and lower latencies. You can look it up in this slide from the 2012 Fusion Developer Summit. You don't want your GPU to be saturated because of both GPGPU algorithms and graphics tasks. A single (AMD) GPU can't handle either task at the same time, which would end in a lot of headache for the programmer. AMD names two solutions for this problem: You can wait for the 2014 20nm feature Graphics Pre-Emption, or you just use an APU dedicated to computing together with a second GPU dedicated to graphics rendering. Sony is doing the latter, obviously.
It seems as if the Orbis rumors are getting more and more specific. The difference between this leak (8 x Jaguar/ 256 GCN SPs APU + 896 GCN SPs GPU) and the last leak (8x Jaguar CPU + 1152 GCN SPs GPU) is a much better balance between the computing power and the graphics power. Eight Jaguars for a Pitcairn seemed a bit underpowered, anyway. But one thing is missing in this leak: There is no dedicated DRM hardware at all, neither ARM nor SPE. It would really surprise me if they are launching without a proper in-hardware DRM.
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