Intel plays with the thought of integrating DRAM into the CPU.  One of the most important goals when designing a new chip is to keep the available processing units as busy as possible. One way to achieve this goal is to feed enough data into the cores as quickly as possible through improved inter-core communication. The progress from one processor generation to another is obvious: For example, while the 65 nm Kentsfield quad-core provided a bandwidth of about 8 to 9 GB/s, the 45 nm Harpertown chip offers 18-20 GB/s. 
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