Tilera Unveils Details for Multicore Chips
By DON CLARK
August 20, 2007; Page B6
Some companies are racing to put a handful of electronic brains on a computer chip. Others, such as Tilera Corp., are laying the groundwork for much more complex creations.
The Silicon Valley start-up, drawing on research that emerged in 1996 from the Massachusetts Institute of Technology, today is providing the first details of its 64-processor chip -- and an underlying design that it says could be used for products with more than 1,000 calculating engines.
Tilera's technology isn't targeted at computers, a market where chip makers such as Intel Corp. and Advanced Micro Devices Inc. are now selling products with two microprocessors on a piece of silicon. Instead, the start-up is targeting special video-processing hardware and networking devices. Tilera says it is shipping its chips now and has about a dozen customers.
The race to develop such "multicore" chips, as they are called, accelerated because techniques for speeding up individual microprocessors are running into limits. But there are obstacles to effectively use vast numbers of microprocessors.
One of the biggest challenges is communications between processors. For that chore, most chip makers now use a data pipe called a bus.
That's fine for up to eight or so microprocessors, says Anant Agarwal, a former MIT researcher who is now Tilera's chief technology officer. Beyond that, he says, chips face data traffic jams -- like too many roads converging on the intersection. "That bus is just getting clogged up," he said.
Just as cities changed their layouts as they grew, Mr. Agarwal in 1996 proposed a grid of interconnections among chips known as a mesh. With that design, signals can pass separately, and simultaneously, between cores on a chip.
Mesh connections were already being used to connect chips within a large computer. But perfecting the same trick within a chip took years, Mr. Agarwal says. Tilera created what it calls "tiles," microprocessors that come with a built-in router to direct data traffic as well as two varieties of cache memory, a kind of short-term data repository.
Each tile can run a standard operating system, such as Linux. That approach, Mr. Agarwal says, helps with another problem -- effectively programming multicore chips. In many cases, companies can quickly adapt existing software to run on a single tile, and then replicate the same program to run across many of them, he says.
Some specialized calculating chores are likely to find the biggest payoff from the technology, Mr. Agarwal says. They include companies that make equipment for videoconferencing, process images from security cameras or sift through billions of data packets looking for malicious software code.
"There really has been an area of the market that needs something like this," says Will Strauss, an analyst with market-researcher Forward Concepts in Tempe, Ariz.
Tilera, of Santa Clara, Calif., will face competition from other start-ups, Mr. Strauss notes. Ambric Inc., of Beaverton, Ore., has a 344-processor chip based on a mesh design that it also believes can scale to thousands of microprocessors, said Leigh Anderson, its product marketing manager.
Stream Processors Inc., of Sunnyvale, Calif., has developed a chip with 80 specialized cores, called arithmetic logic units, arranged in 16 groups to allow data to move through the product at very high speed, the company says.
Both Ambric and Stream Processors say that they, like Tilera, have begun shipping their chips.