Via Technologies has provided the first detailed look at its upcoming Isaiah processor architecture, demonstrating technological and performance improvements that could determine whether or not the company can take on Intel and AMD in the processor market.
Via is counting on Isaiah to become a mainstream processor vendor instead of a niche player in this market. The importance of achieving that goal can't be understated. Via's third-party chipset business, historically its largest source of revenue, is dying and the company's future hopes rest on the sale of its own processors and related components.
Isaiah is dramatically different from the processor design used in Via's current C7 lineup. Where the C7's Esther core uses an in-order architecture that processes one operation at a time, the 64bit Isaiah architecture uses a superscalar, out-of-order architecture capable of processing multiple operations at the same time, said Glenn Henry, president of Centaur Technology, the Via subsidiary in Texas, that does processor design for the Taiwanese company.
An in-order processor is similar to a factory with a single assembly line. The chip can only work on one operation at a time, and other operations must wait for the assembly line to clear before they can be processed. An out-of-order processor is equivalent to a factory with multiple assembly lines, where different operations can be processed simultaneously.
Because Isaiah uses a superscalar design, multiple instructions can be processed during every clock cycle. These two improvements boost its overall performance and give the chip from two to four times the performance of the C7, while consuming the same amount of power.
"It doesn't need a bigger fan, it doesn't need a bigger heatsink. You just get more performance," Henry said.
Isaiah also offers significantly more on-chip cache than Esther-based C7 chips. Current C7 chips have 128KB of level 2 cache, while Isaiah will have 1MB. The new architecture also supports a front-side bus speed up to 1.3GHz, compared to 800MHz for Esther. Processors based on Isaiah will run at speeds from 400MHz to 2GHz, the same as Via's existing C7 chips.
Isaiah includes support for virtualisation, a technology that's primarily used today in servers but will eventually find its way into client devices for improved reliability and security, Henry said.
The chips, which will initially be manufactured using a 65-nanometre process, will be pin-compatible with the C7, which means device makers don't need to redesign their products to use the new chip, he said.
Originally intended to be released in 2006, Isaiah nevertheless arrives at an opportune time for Via.
Growing demand for small, handheld computers has created new customers for the low-power C7. This segment of the market is expected to grow quickly in coming years. And the market will get a further boost year when Intel announces its Silverthorne processor and makes a concerted effort to promote these types of devices.
Henry expects Isaiah processors to outperform Silverthorne, based on the limited information that Intel has made available about its chip. And while Via can't hope to match Intel's clout in the computer industry, company executives hope Isaiah's improved performance will be good enough to win more market share.
"It's a significant improvement over the C7," said Dean McCarron, president of Mercury Research, a market research firm that tracks the microprocessor market.
"Assuming that they deliver on the schedule they are quoting, [Isaiah] should be a very good product for them," he said.
Unlike many of Intel's latest processors, Isaiah chips will have a single core, even though the architecture will work with multiple cores. Adding a second core adds more transistors and increases the size of the chip, which in turn increases power consumption and current leakage.
"Even when it's not being used, it's leaking," Henry said.
Gains in active power consumption that come from having two cores are offset by a lack of software designed for small computers and portable devices that takes advantage of processors with multiple cores.
"If what you're doing is watching a movie, browsing the web, sending email, and using a spreadsheet now and again, you wouldn't see any benefit from dual core," he said.