Intel will likely be first to market with a quad-core x86-based processor early next year. But when the company unveiled the design of its quad-core processor at the Intel Developer Forum this week, it raised questions as to whether the processors really deserve the label "quad-core."

Using a similar strategy that it used when it introduced its first dual-core offerings, Intel plans to offer a multichip package that combines two of the upcoming dual-core Woodcrest Xeon processors to create its first quad-core processor for servers. Similarly, Intel plans to use two of its soon-to-be-released dual-core Conroe processors to create its Kentsfield quad-core processor for desktop PCs.

Intel used two single-core Pentium processors in a multichip package to create its first dual-core offering last year, the Pentium D. Intel later in the year introduced dual-core versions of its Pentium and Xeon processors that used a more conventional monolithic silicon substrate.

Advanced Micro Devices, by contrast, has used a monolithic, or what the company calls "native," implementation on it all its dual-core processor offerings. Brent Kerby, product marketing manager for AMD, says the company will again use a monolithic design for its first quad-core offerings, scheduled for the second half of 2007.

Nathan Brookwood, an analyst with Insight 64, says the use of two separate pieces of silicon combined in a single package to create a dual-core or quad-core processor doesn't inherently make it a "less legitimate" multicore processor than a monolithic design. The use of multichip packaging to create its initial dual-core and quad-core processors has allowed Intel to get its new processors to market faster, he says. The result of a multichip packaged offering, however, is likely to net less of a performance gain than an equivalent monolithic design.

Although Intel executives at IDF didn't confirm plans to eventually introduce a monolithic quad-core processor, Brookwood says he believes Intel will make the move when it transitions from its current 65 nanometer manufacturing process technology to the 45 nanometer technology. The smaller-geometry manufacturing process will let Intel put the additional transistors of the quad-core structure in a smaller physical size than would be possible with a 65 nanometer process.