NEC Readies VCM Core; Intel Not Yet On Board

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October 05, 1998 (7:37 AM EDT)

NEC Readies VCM Core; Intel Not Yet On Board

Having assembled third-party chip-set support for its virtual-channel memory (VCM) architecture, NEC Electronics is poised to thrust the new 133-MHz synchronous DRAM (SDRAM) core into the notebook and low-cost desktop-PC markets.

However, without the endorsement of chip-set industry leader Intel, which has thus far withheld its blessing, many observers said they predict NEC's VCM core will have a tough go of it in the broader market.

NEC, which released details of its VCM technology less than a year ago, has moved quickly to build an industry framework to drive the core into laptops and so-called value-line desktop PCs.

In addition to receiving full Joint Electronic Device Engineering Council committee approval as an open industry standard in August, the U.S. arm of Japan's NEC has garnered second-sourcing support from Siemens AG's Semiconductor Group. NEC expects to disclose other DRAM sources this month, and industry observers said the company is working closely with PC OEMs.

NEC will also reveal next week that chip-set vendors Acer Laboratories, Silicon Integrated Systems (SiS), and Via Technologies will roll out VCM-enabled chip sets as early as this month, with volume supplies coming later in the fourth quarter. Together with its industry partners, NEC said it expects VC-SDRAM to penetrate the sub-$1,000 desktop-PC market in systems coming out in the first half of 1999.

However, while Acer, Via, SiS, and other third-party chip-set makers share about 40 percent of the value-line PC market, the noticeable lack of support from chip-set market leader Intel could hinder VCM's adoption rate, said Mario Morales, an analyst at IDC, in Mountain View, Calif. "Until NEC gets Intel, it's going to be very difficult to standardize a solution," he said.

Intel, which has spent time and resources moving memory and PC makers alike toward a 1999 adoption of the Direct Rambus DRAM interface, didn't rule out future support for VCM. However, the company has made no publicly stated provision for the architecture in its road map.

"Our memory direction is clear," said a spokesman for the Santa Clara, Calif., chip maker. "We support Direct Rambus, and we're going to enable that in 1999."

VCM is said to improve conventional SDRAM cores by adding SRAM registers to temporarily store data in 16 distinct channels between the I/O terminals and memory cells. Operating at a 133-MHz clock rate, the SRAM buffers increase peak bandwidth to about 1 gigabyte per second, according to Michael Ham, product marketing engineer for NEC's memory group in Santa Clara, Calif.

"Our memory direction is clear. We support Direct Rambus, and we're going to enable that in 1999."
-- spokesman
Intel

To make room for the SRAM registers, NEC removed the VCM core's control circuitry, moving logic functions to the memory controller. The die size and cost of a VC-SDRAM exceeds that of a typical SDRAM by about 3 percent, but improves system-level performance by up to 25 percent, according to supporters. In systems built on a unified memory architecture, that premium may be somewhat lower because of VCM's ability to replace Level 2 cache, NEC said.

In a notebook PC, VCM can lower memory power consumption by up to 50 percent, according to Ham, because the addition of SRAM registers minimizes the number of page misses, limiting how often the SDRAM banks must be activated.

In the sub-$1,000 desktop-PC market -- a segment in which non-Intel chip sets and microprocessors have made appreciable gains -- VCM-enabled systems will sport an array of new chip sets, including the MVP4 from Taipei, Taiwan-based Via, which is slated for production later this year.

Because VC-SDRAM is a core, not a memory interface like Direct RDRAM or SLDRAM, it requires no changes to pinouts or packages, which simplifies the design process. "It's a no-brainer," said Dean Hays, vice president of marketing at Via's U.S. operations in Fremont, Calif.

According to NEC, VCM-enabled chipsets will feature scaleable front-side bus speeds ranging from 66 MHz to 133 MHz. In addition to supporting VC-SDRAM chips, the new chip sets will support PC-100/66 SDRAM and EDO memory. All the chip sets will feature full AGP support, and some will have an integrated 3-D graphics controller, according to NEC.

Exactly how VCM will interrelate with other memory architectures coming onto the market is unclear. At about the same time VC-SDRAM-enabled PCs enter the value-line computer sector next year, several OEMs are expected to unveil high-end desktop systems using Direct RDRAM.

Eventually, the two technologies should cross into the same performance class, at which point Intel could consider offering chip set support for the VCM architecture and meld the Rambus interface with the new SDRAM core, analysts said.

"We'll have Rambus coming down from the top and VCM coming up from the bottom, and, at some point, they'll meet," said Steven Cullen, an analyst at In-Stat, in Scottsdale, Ariz. "They could meet and merge."

Rambus, in Mountain View, Calif., said all its Direct RDRAM licensees have the ability to design VC-SDRAM-compatible chips, including NEC, which has not yet made a move in that direction.

Rambus said it predicts VCM will have to earn respect in the market, and the two technologies will have to enter the same price/performance sphere, before they are brought together.

"The one thing NEC really needs more than anything else is chip-set support. Until they get it, [VCM] isn't going to gain any prominence."
-- Jim Handy
Dataquest

"If somebody can prove the core at the low end, then we're confident with all the DRAM licensees out there, some company will merge the two," said Subodh Toprani, vice president and general manager of Rambus' logic division.

However, while its long-term prospects look good, until Intel launches a VC-SDRAM chip-set program, the technology could have difficulty breaking into more mainstream markets, said Jim Handy, an analyst at Dataquest, in San Jose, Calif.

"The one thing NEC really needs more than anything else is chip-set support," Handy said. "Until they get it, [VCM] isn't going to gain any prominence."

-- Mark Hachman contributed to this story.