DDR3 SDRAMs for PC main memory are expected to ramp in 2008 or sooner, while Rambus Inc.’s XDR technology will remain a “niche product” for game machines, according to Jon Kang, senior vice president for the technical marketing group at Samsung Semiconductor Inc. (San Jose, Calif.), the U.S. chip arm of South Korea’s Samsung Electronics Co. Ltd. (Seoul).

In 2003 Rambus (Los Altos, Calif.) took off the wraps and provided more details of its next-generation memory interface technology, formerly known as Yellowstone. Rambus, along with Japan's Toshiba Corp. (Tokyo) and Elpida Memory Inc. (Tokyo), rolled out the technology, now called XDR DRAM. Samsung is also working on XDR memories.

Last year, Rambus announced the latest version of its high-bandwidth XDR memory interface technology, named XDR2. The XDR2 memory interface uses a micro-threaded DRAM core and circuit enhancements that enable data rates starting at 8-GHz frequency switching, making it five times faster than today's best-in-class GDDR graphics DRAM products, according to Rambus.

Sony Corp. (Tokyo) is using XDR technology in the Playstation 3, but the game machine was delayed until November.

“XDR has been delayed [due to delays at Sony],” Kang said during a presentation at SEMI’s recent Strategic Business Conference here. “I don’t see any applications for XDR beyond Sony. It’s a niche product.”

There is more potential for the follow-on to current DDR2 SDRAM memory technologies for PCs, dubbed DDR3. Most — if not all — DRAM makers are working on DDR3 technology.

The real key is Intel Corp., which must ship a chip-set that supports DDR3 in systems. Some believe that Intel will ship the chip-set in 2007, thereby opening the door for the DDR3 era.

In a more likely scenario, Kang said that DDR3 is expected to ramp in the 2008 time frame. “Intel sets the pace and everyone follows,” Kang said. “Intel says [DDR3] will happen in 2007, but I don’t believe it.”