There are a couple of options to help speed up the flow of data from the memory controller to the FSB. One is to use dual-channel memory, so the buffer will fill up in half the time. This helps to explain why Intel benefits more from dual-channel RAM than AMD: their FSB and memory controller are really designed for the higher bandwidth. Another option is to simply get faster RAM until it is able to equal the bandwidth of the FSB. Either one generally works well, but having a memory subsystem with less bandwidth than what the FSB can use is not on ideal situation, especially for the Intel design. This is why most people recommend against running your memory and system busses asynchronously. Running RAM that provides a higher bandwidth than what the FSB can use does not really help, other than to reduce latencies in certain situations. If the memory can provide 8.53 GB/s of bandwidth and the FSB can only transmit 6.4 GB/s, the added bandwidth generally goes to waste. For those wondering why benchmarks using DDR2-533 with an 800 FSB P4 do not show much of an advantage for the faster memory, this is the main reason. (Of course, on solutions with integrated graphics, the additional memory bandwidth could be used for graphics work, and in servers, the additional bandwidth can be helpful for I/O.)
This was from an AnandTech posting. My question is answered.
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