Any reason why Sandy Bridge EX is (assuming the report is true) 4P and not 8P besides market differentiation from Westmere EX?[/.QUOTE]
The interconnect bus would be scaled down (but done intentionally to create a product point).
My guesses are 6/8 cores for Sandy Bridge EP and 8/12 for Sandy Bridge EX, assuming that the latter is single-die (more likely than dual-die I think).
They're going to be single die.
would the read/write of the communications bus be the bottleneck though? i mean, even if you do have say, 3 RAIDs, you can only send one chunk of data from one HDD RAID at a time? or not :\
If there's more data than can be transferred across it, then Yes. But QPI was a substantial improvement in this regard (what we have in the Nehalem's is cut down, but it's full scale on the 75xx parts - much more band than is possible in DP systems).
sooo to save themselves money, they drop off a few cores? well thats just stupid. its like buying a car with 8 potential cylinders, but only allowing 6! what on earth :\
That's not what usually happens though. I meant in being able to get a CPU to run at higher frequencies, the current processing isn't really capable of getting high yeilds at those clocks.
That's why they bin them in the first place (well, one of the reasons). It allows them to grade the speed they're stable at, and find units with portions out of spec (or even non-functional). So the end result is both what parts are marked as what P/N (clock speed), and whether or not parts will be sent to the nano surgery section for modification (i.e. made into a P/N with fewer cores, when it had more to start with, as something failed).