How FB-DIMM Memories Work

Capacity and Performance

In Figure 4, you can find a summary regarding FB-DIMM capacity and performance advantages.

Using regular DDR2 memory modules, the maximum memory subsystem you can build is 8 GB and 10 GB/s transfer rate, if you use four DDR2-DIMM sockets, two channels, and DDR2-800 memories.

With FB-DIMM, the maximum capacity jumps to 192 GB. The transfer rate jumps to 40 GB/s if you use 48 modules, six channels, and eight modules per channel, using the same memories (DDR2-800).

Figure 4: DDR2-DIMM vs. FB-DIMM capacity comparison

The FB-DIMM idea is really interesting and should solve the demand for high RAM capacity servers, especially if we think that new CPUs from both Intel and AMD can access far over 4 GB of RAM when using 64-bit operating systems. So far, several memory manufacturers have already announced that they will manufacture FB-DIMM parts, including Samsung, Elpida, Infineon, Micron, Hynix, Nanya and Kingston.