You: "The "special" video card slot throughout history has simply been a higher bandwidth interconnect relative to whatever else was there..."
Me: "One of the challenges of GPU performance is getting the connection between the CPU and Memory correct. "
Yes, its the GPU <-> (CPU/Memory) interconnect. It has, since the introduction of PCI, been a 'different' slot than other peripherals. So I don't see how we're confused.
You: ""CUDA" is an NVIDIA trademark for their compute platform, it's not a special kind of technology. ... the Industry terminology is a mess)."
Me: "CUDA, or more accurately, running general purpose compute tasks on shader engines."
The industry terminology is a mess, however most readers recognize the name 'CUDA', nVidia's implementation of a shader language, as that technology. Further it was the introduction of using shaders as vector units which lead to folks implementing things like the 'PS2 supercomputers'. (and to be precise, no you cannot use nVidia's tools on PS2s)
You: "Honestly, I think rwmj is right: for a consumer gaming rig, it would be preferable to have an 8 core part without integrated graphics."
Which is great, what I would love to see then is how you reason to that opinion. What is it about the 4 additional cores that would improve the 'consumer gaming rig'. How are you measuring 'good' vs 'not as good'? Cost? Triangles per second per dollar? Developer support?
"Second (and relatedly) they already do make "lots of cores w/o graphics" variants, but they sell them into the low volume server market where margins are much higher. Selling an 8 core consumer chip would canibalize Xeon sales."
I don't think anyone has argued that Intel couldn't make an 8 core processor out of this technology, heck the feature size is small enough they could probably to 12 or 16 cores and still get decent yield, but there are other system issues associated with that, most notably cache behavior and size.
But the specific question on the table was that Intel has made a part which they expect people to put into laptop machines and maybe even tablets. They chose to make it a four core machine with an integrated GPU, are you arguing that the consumer experience on those laptops would be improved if Intel required an external GPU? If so I'd be interested on your take on that as well. First, the way you evaluate value, and then the case for an external GPU that maximizes that value.
"CUDA" is an NVIDIA trademark for their compute platform, it's not a special kind of technology. In fact Intel's i915 derived GPU works very similarly. In fact, Intel's AVX instructions also work along basically identical lines. They're all wide SIMD implementations of a bunch of parallel tasks(/threads/lanes/warps, the Industry terminology is a mess).
Honestly, I think rwmj is right: for a consumer gaming rig, it would be preferable to have an 8 core part without integrated graphics. The reasons that isn't going to happen aren't technical though: first, Intel needs to ship different binnings of these same parts into segments (Ultrabooks, tablets) where the graphics are required and where price is more constrained -- basically, they have to make these in large quantities anyway. Second (and relatedly) they already do make "lots of cores w/o graphics" variants, but they sell them into the low volume server market where margins are much higher. Selling an 8 core consumer chip would canibalize Xeon sales.