Vendors detect early shift to 'busless' boards: shaving silicon cost on interface a tactic

Electronic News, Nov 2, 1992 by Craig Stedman, Jonathan Cassell

Shaving Silicon Cost On Interface A Tactic

Makers of VMEbus boards are shifting some of their attention to busless single-board implementations as they try to become more competitive with alternative technologies in lower-end functions such as embedded control. The strategies essentially involve shaving off bus interface silicon costs and other expenses.

Busless boards began appearing on the market in earnest this year and are expected to become more widespread during 1993 and 1994--due in part to an increase in the cost of interface silicon anticipated once a new higher-performance version of the VMEbus standard now in the works is codified.

Ray Alderman, technical director of the VMEbus International Trade Association (VITA), predicts busless single-board computers could account for close to 20 percent of board sales by as early as next year, up from a very small percentage today. He said "1993 is when everyone that's going to do it gets out there and makes a run for it."

Some individual vendors going the busless route expect it to provide 25 to 30 percent of their business in coming years. "People here joke that we should just get out of the VME business, although we won't," noted X. Kim Rubin, vice president of engineering at GreenSpring Computers, Menlo Park, Calif.

Others are more cautious about short-term busless board prospects. Motorola--VME market leader--introduced a 68040-based busless unit last summer, but doesn't expect to field any others for another year or so while it gauges the success of the first offering.

"Quite honestly, we're taking a wait and see attitude right now," said Dennis Liles, product manager for VME boards at Motorola. "We're primarily a VMEbus and VME systems house, and we're not going to make any radical departures here."

Mr. Liles, however, agreed a busless trend is likely to affect conventional bus board shipments to an extent. "We will see an erosion," he said. "The question is how much? It's hard to gauge because there's not that much hard information available yet."

The busless concept, in which boards function on a standalone basis without special backplanes or chassis, has been around for years, but board vendors didn't actively pursue the idea until a recent mix of market, economic and technical factors pushed them to do so.

The weak economy has companies looking for new business channels in general, at a time when the rise of the PC has made it harder for bus boards to compete at the low end. Meanwhile, increasing technical integration has made single-board computers more feasible, and the development of so-called mezzanine buses allows I/O to be tied directly into a board rather than having to use a full system bus.

While vendors hope much busless business will come at the expense of PCs and programmable logic controllers rather than bus boards, Mr. Alderman said "a lot" of the sales involving older buses like the 3U VME form factor and the rival Multibus I and STD technologies "could potentially go away" as busless boards become more common.

The cost savings on busless boards varies. PEP Modular Computers has a single-quantity price of $535 on the busless version of its 68302-based 3U board, compared to $1,055 with the VME interface, but other companies reduce prices by smaller percentages. Motorola's MVME- 162 board is $1,045 busless and $1,295 with VME, while Force Computers sells its Sparcstation 2 single-board for $7,495 (busless) and $7,995 (with bus).

Going busless typically should give OEM customers the potential for additional savings beyond the price of the board itself, though. The elimination of the VME backplane and chassis also reduces costs, and development time would be expected to be shortened as well.

"Just taking the interface off doesn't save that much," Mr. Liles said. "It's not having the complexity of the backplane or the chassis. That really gives you an over-all lower cost, plus a faster time to market for the developer (that's buying the boards)."

Busless implementations would typically cost a half to a third as much as bus-based ones, Mr. Alderman added, "and in some extreme examples you might even see a one-to-five ratio." He and others expect the difference to widen further once the proposed new VME standard covering 80MBps and 160MBps transmission rates is finalized (EN, Sept.28).

"All of a sudden, VME is going to have these expectations of higher performance, and that costs money," said Tom Griffiths, manager of product marketing at Campbell, Calif.-based Force. "It takes fast logic to make that possible, and a lot of customers are going to say they don't need that kind of performance and so they don't want a bus."

In fact, this is already been happening with the current 40MBps technology, he added. "A lot of people are only using one of our boards in a system anyway, so they're not using the bus and would be just as happy with a little less silicon on the board and a $500 lower price."

Mr. Rubin noted GreenSpring received 10 times the customer response it expected from a card-stack ad for its initial 68332-based busless board earlier this year.