Bobcat only seems to support SSE3 (and SSE4A which is not related to SSE4).Bobcat supports SSE4.1 at least doesn't it? How does that instruction set compare to the revision of AVX found in the 360?
I'm not sure exactly what instruction set the xbox 360 powerpc core supports.
Hmm atom is roughly 20 million transistors on 10 mm^2 (core only without L2) right? That isn't particularly dense indeed.the design methodology used in the atom could explain the large size of the cores.
If Ontario is really cedar with 2 bobcat cores bolted on, that would mean the 2 bobcat cores (including L2) would take up around 90 million transistors. Subtract L2 and each bobcat core would be around 20 million transistors. So, a bobcat core indeed would have similar transistor count to a atom core, but simply be packed in a much smaller area.