While the future of FB-DIMMs is uncertain due to AMD's lack of adoption and the upcoming Microbuffer memory technology, FB-DIMMs remain the latest and greatest for Intel's Xeon platform. The results in this article speak for themselves, and as expected, there were minor performance improvements in all of the benchmarks when stepping from a single channel to dual and finally four FB-DIMM memory channels. Even though FB-DIMM memory modules have been out now for several months they remain much more expensive than traditional DDR2 server memory. The Kingston KVR533D2S8F4/512 modules retail for approximately $90~100 USD per 512MB module. We have not run into any technical problems with FB-DIMM memory and Intel's Xeon 5300 series.
Look for more in-depth Intel Xeon performance articles in the future at Phoronix and more information on the Phoronix Forums.