If you read the interview with Rambus a few weeks back, you heard about the potential advantages that XDR DRAM offered over tradtional DDR SDRAM and other types of memory. Elpida has now begun sampling XDR RAM, starting with 512Mbit chips that operate at 400MHz, achieving a "4GHz data rate", which in theory leads up to a throughput of 8GByte/sec on a single stick, a significant improvement (nearly 4x) over traditional RAM. They are built on a 90nm process and use a ball grid interface instead of pins. The RAM is already being sampled to certain manufacturers, and is ultimately destined for high-end entertainment systems and servers, and other super high performance devices.