The folks over at X-Bit labs take their time demystifying the inner workings of dual-core architecture in their latest article. Using some clever benchmarking techniques, they aim to compare data transfer rates between AMD and Intel's dual core CPUs.
"The processors are working with data that are read from system memory to be modified and then written back. Data are cached in the CPU for faster processing, but more than one processor may request the same data in a multiprocessor system. This is not a problem if both the processors are just reading data, because they are both provided the most recent valid copy from system RAM. But if one of the processors modifies the data, the data are first changed in the cache memory and it is only after a while that they are written into system RAM. So, there is a potential conflict when one processor is trying to read data that have been modified and are currently stored in another processor's cache."