Elpida has begun sampling 4 GB FB-DIMM DDR2 memory modules and will start volume production in the fourth quarter. Two models will be initially available. The PC2-4200F runs at 533 MHz with 4-4-4 latency timings and the PC-5300F runs at 667 MHz at 5-5-5. Modules are only 6.7 mm thick, which, according to Elpida, improves cooling. FB-DIMM is an open standard developed by Intel and aimed mainly at servers.