Rambus Inc. engineers claim they have developed the world's fastest bus technology. They demonstrated the company's memory bandwidth technology during the International Solid-State Circuits Conference (ISSCC) in San Francisco this week. Some see the announcement as an attempt by Rambus to head-off competitive double-data-rate memory transfer technologies that may lead to less expensive high-performance workstations.

The Los Altos, California-based bandwidth chip connection technology developer demonstrated a 2G-bps (bits-per-second) transfer rate per channel with its QRSL (quad Rambus signaling level) technology. This bumps up the QRSL throughput from the 1.6G-bps level that was first announced in June 2000 -- a level which is expected to be incorporated into RDRAM (Rambus dynamic random access memory) by late 2001, said Kristine Wiseman, a Rambus spokeswoman.

QRSL combines DDR (double-data rate) technology along with multi-level signaling to transfer four bits per clock cycle and ultimately provide throughput from up to four memory sources to the system memory controller at 2G bps.

At least one analyst suggests that Rambus' demonstration may have been more of a positioning statement to the industry.

"This announcement is likely to be a result of the pressure from the other vendors that are pushing DDR as a high bandwidth solution," said Cary Snyder, a senior analyst with research firm MicroDesign Resources.

HDTV (high-definition television), game consoles and set-top boxes could be typical applications for RDRAM using the signaling technology, Rambus' Wiseman said.

"It is usually a consumer product which requires increased bandwidth out of the fewest number of devices," Wiseman said. "The reason we say a consumer device is because they don't use connectors or memory modules. It is a non-upgradeable type of appliance. The key is highest bandwidth with fewest devices."

The 1.6G bps is twice the bandwidth of the RSL (Rambus signaling level) technology found in most RDRAM devices like PCs, workstations and consumer appliances. Also at the ISSCC conference, Rambus demonstrated RSL technology that provides 2.1G bytes per second (1.1G bps) of bandwidth from a single device on a Rambus channel.

Despite its high performance, RDRAM has failed to take the PC market by storm. Until Intel Corp. last year released its high-end Pentium 4 processor for desktop PCs, which currently can only be used in systems featuring RDRAM, memory makers such as Seoul-based Samsung Electronics Co. Ltd., among the early backers of the technology, found the speedy, but costly, memory chips a hard sell.

With Intel's support for the Rambus technology, however, Samsung expects to dedicate as much as 30 percent of its total DRAM production capacity in 2001 to making RDRAM chips, said Jon Kang, senior vice president of product planning and application engineering in Samsung's memory technology and product division.

"As the only memory solution for the Pentium 4, Rambus will ramp very quickly this year," Kang said. Samsung has manufactured RDRAM chips since 1999, but Kang admitted that the company had been "quite disappointed" by the lack of demand until the arrival of the Pentium 4.

Nevertheless, Samsung is also backing DDR SDRAM (synchronous DRAM), a competing high-speed memory technology, which is expected to make up 10 percent of the company's total DRAM output this year, Kang said, and continue to ramp up quickly next year. RDRAM, however, is likely to remain popular among users requiring the highest-performance desktop computers, he added.

Kang and other executives at some of the world's largest memory makers, including Elpida Memory Inc., Infineon Technologies AG, Hyundai Electronics Industries Co. Ltd. and Micron Technology Inc., were in Taipei Tuesday for a DDR Summit conference hosted by Taiwan-based PC chip set and processor vendor Via Technologies Inc.

Most of the executives seemed to agree that DDR SDRAM eventually will become the memory technology of choice for use in a broad array of computers, ranging from desktop and notebook PCs to servers and workstations as well as in other digital devices.

Samsung better enjoy the boom in RDRAM sales "while they last," quipped Farhad Tabrizi, vice president of worldwide memory product marketing at Hyundai.

More on ISSCC and chip futures

» posted by ITworld staff

IDG News Service

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