Intel's Clovertown may fall short

An upcoming Intel quad-core Xeon server processor, codenamed Clovertown, likely contains two dual-core chips in a single package, according to an industry analyst, who warned the processor may not offer a significant boost in performance.

"Intel hasn't said whether it architected Clovertown as a quad-core processor, or merely combined a pair of dual-core chips in a multi-chip package," said Nathan Brookwood, an analyst at Insight64, in a research note. Clovertown is expected to hit the market in early 2007.

While Intel has yet to offer details of the Clovertown design, Brookwood believes the chip uses two Woodcrest dice, or pieces of silicon, housed in a single package. Woodcrest is the codename of an upcoming dual-core Xeon chip developed by Intel, he said.

Intel used a similar "ad hoc" design for its first generation of dual-core processors, which included either two cores on a single die or two single-core dice housed in one package, Brookwood said.

"We've seen this movie and it didn't have a happy ending then, either," he wrote.

The problem is performance. Intel's earlier dual-core chips contained two cores that shared a single front-side bus, which is housed outside the chip, Brookwood said. The front-side bus connects a computer's processor with main memory. While Intel's first dual-core chips outperformed a single-core chip, a better dual-core design would likely have meant even greater performance, he said.

The Blackford chip set designed to be used with the dual-core Woodcrest chip addresses the performance issue in earlier chips by offering two independent front-side buses, one for each core. However, those same performance issues return with the Clovertown design, which has two cores sharing each of Blackford's two front-side buses, Brookwood said.

As a result of this design choice, Clovertown's performance will only be "marginally better" than Woodcrest in most applications, Brookwood said. The performance would be better if Intel used a better processor architecture, he said.

"We are confident that eventually Intel will introduce quad-core Xeon processors with competitive performance, but we doubt that Clovertown will be the vehicle that meets this target," he wrote.