How Intel could deliver dual core chip prototypes

CHIP ANALYST NATHAN Brookwood at Insight64 has clearly got the bit between his teeth, in the race to understand how Intel will deliver dual core chips within the time frame it promised at its Developer Forum just days ago.

Brookwood, in a document sent to clients, said that after he released a report last week, some readers suggested he used too broad a definition of engineering prototype. According to some of his readers, a dual core prototype has to, at a minimum, have two processor cores on a single piece of silicon.

"Intel would be misleading its audience it it tried to fit any other implementation under the dual core label," said Brookwood. "They [the readers] argue further that Intel would not be willing to risk its reputation for high integrity, just for the sake of a product demo at a conference".

Brookwood said a technically skilled employee of Insight 64 has come up with a scheme which doesn't require changes to silicon designs or masks, but might well require a new type of packaging which would, however, be compatible with LGA 775.

As Intel makes its chips on 12-inch (300mm) wafers, each of which holds around 500 individual microprocessors, it then separates the individual dies and packages the processors that pass the tests. A typical wafer, he suggests, yields between 250 and 400 good chips.

He said: "There will be many instances where two, four or even eight contiguous processors are all defect free". If Intel keeps the pairs of good chips togehter, it would need a package to hold the larger chip - something around twice the size of a single core CPU.

But the new package would have the same pinout and footprint as current Pentium 4s, he suggests, with "internal connections that distribute bus signals and power to both cores".

He points out that such a scheme will work with current Pentium 4 mobos, but each of the CPUs would clock lower and use less voltage.

"Few would complain if these prototypes required exotic liquid cooling technology. The scheme is even extensible for quad core prototype development," he said.

He concluded that Intel may well have used this type of approach to make the chips it demoed at the Developer Forum. And the pics above show how it might have been done. µ

L'INQ
Insight 64