In particular, Brewer and other AMD executives cited a recent study from Mercury Research pointing out that quad-core processors represented less than two percent of desktop shipments during the second quarter, while dual-core took up the remaining 98 percent. Until demand ramps up for quad-core, triple core will serve as something of an intermediary, according to AMD. At the same time, the company hopes it will also stimulate broader multi-core adoption.
"We left the megahertz race for the core race," said John Taylor, product communications director at AMD. "The sweet spot is now four (cores) and down … and there are a lot of scenarios where three cores outperforms dual core," he said.
Nathan Brookwood, an analyst at Insight64, agrees.
"I think it could be clever," said Brookwood, who was also at the briefing. "Conceivably, a tri-core chip from AMD could run 20 percent faster than a quad-core chip and feature a 15-16 percent performance boost for each thread. That would be interesting to many users."
(((In terms of architecture, Brewer also confirmed on Monday that the yet-to-be named processor will basically be a quad-core processor with one core disabled, and that it will feature the company's Direct Connect architecture, as well as a shared L3 cache, and other architectural selling points that Intel currently lacks.)))
From what I can tell based on what has been announced, the new triple-core Phenom is essentially what The Inquirer described it as—((a quad-core Phenom with one core disabled.)) This should help alleviate some of the yield issues that are bound to plague a part this size, but only if the tri-core actually sells
Why a three-core chip? There's definitely a manufacturing edge to be gained there: Not all of the CPUs that come off a wafer will work properly. The native quad-core design AMD's using for Phenom (and the Barcelona server CPUs it just released), makes it easy for the company to ((deactivate a defective core)) and still have a viable three-core chip. Sony does something similar with the Cell processor in the Playstation 3 shipping with seven of its eight SPE cores operational.
Ever since AMD has announced its tri-core, most of the drama has been around the fact that it is most likely a ((defective quad-core, with one disabled unit.)) It is obvious that it would save AMD money to resell chips that would otherwise go to the trash bin
Of course, no one sets out to make a three-core product - AMD is simply being commercially canny. Of all the quad-core chips it punches out, some will have cores that are dead or not up to scratch. AMD can't sell them as four-core products, and while it might have once sold them as dual-core chips, by disabling one of the remaining cores, it now plans to offer them as three-core CPUs.
That allows it to not only sell chips it might otherwise have had to discard or offer as cheaper, two-core parts, but also allows it to position the three-core products as superior to Intel's rival Core 2 Duo chip.