The Core i7 design is based on current Core 2 processors but has been widely revised, from its front end to its memory and I/O interfaces and nearly everywhere in between. The Core i7 integrates four cores into a single chip, brings the memory controller onboard, and introduces a low-latency point-to-point interconnect called QuickPath to replace the front-side bus.
Intel has modified the chip to take advantage of this new system infrastructure, tweaking it throughout to accommodate the increased flow of data and instructions through its four cores. The memory subsystem and cache hierarchy have been redesigned, and simultaneous multithreading—better known by its marketing name, Hyper-Threading—makes its return, as well. The end result blurs the line between an evolutionary new product and a revolutionary one, with vastly more bandwidth and performance potential than we've ever seen in a single CPU socket.