Chicago (IL) - DRAM maker Elpida today announced that it has shipped samples of its Fully-Buffered Dual in-line memory modules (FB-DIMM), The devices provide a data rate of up to 4.8 Gbit per second, equivalent to 6.4 GByte per second (GB/s) data bandwidth. Currently available DDR2 Registered DIMMs offer a throughput of 3.2 GByte per second.

The FB-DIMMs technology foundation is common DDR2 SDRAM, but features a revised module design. All signals (clock, address, command and data) to and from the DRAM on the module are buffered at the high-speed advanced memory buffer (AMB) chip located on the DIMM. This helps to secure the DRAM timing margins during high-speed operation with a much shorter signal path between the DRAM and the AMB, Elpida said.

The FB-DIMM also adopts a Point-to-Point connection on the bus between the memory controller and the DIMM, as well as between the DIMMs, which enables increased bus speed with a shorter connection path. The technology also allows more DIMMs (up to eight 2-rank DIMMs) to be loaded on the bus "with less concern about signal degradation", according to Elpida.

The initial samples shipped by Elpida are currently being used to test upcoming server platforms. Elpida plans to offer FB-DIMM products in 2 GByte, 1 GByte, and 512 MByte densities. Commercial availability of the modules is scheduled for the second half of 2005.

According to the company, FB-DIMMs target "next-generation servers". The specification of the technology already is completed and is up for standard approval at the Joint Electron Device Engineering Counsel (JEDEC).