Details Leak on AMD's Upcoming Hexa-Core Processor

There's been an invisible hexa-core processor lurking on AMD's desktop roadmap ever since the company launched Shanghai on 45nm, but the company has refused to confirm or deny that such a chip was in the works—until now. As of today, AMD's hexa-core desktop processor—codenamed Thuban—is officially on the board. Exact launch dates aren't yet available, but we've got a few details on the core architecture. For those of you who care about this sort of thing, Thuban is a star in the constellation Draco and was once a pole star roundabout 3000 BC.(Six inch clear platform heels are much older than anyone realizes -Ed).

Thuban, like Istanbul, will be a monolithic core and will utilize the same 45nm process as its cousin in the server space. In a surprising move, AMD has apparently confirmed that the upcoming processors will be drop-in compatible with AM3, AM2+, and AM2 motherboards. If that turns out to be accurate, Socket AM2/AM2+ owners that first bought boards when 90nm dual-core Athlon 64 X2's were all the rage will be able to upgrade to 45nm hexa-core processors that could well occupy the same power envelope. The Phenom II X6, as it's expected to be known, will reportedly carry 3MB of L2 (512K per core) and a 6MB unified L3 cache. While this has yet to be confirmed, it's probably accurate; the L2/L3 cache configuration on Thuban is identical to both Istanbul and Shanghai. AMD isn't spilling the beans on any of its launch frequencies at this point, but a glance at the company's current product line, plus a little educated guessing, can get us pretty close.

Istanbul, Constantinople and now Thuban

Based on the company's current lineup of Phenom II, quad-core Opteron, and hexa-core Istanbul processors, Thuban will likely debut at or around 3GHz, with a TDP between 95-125W, depending on how mature the 45nm production lines at GlobalFoundries are by then. Scaling Thuban will be tricky; there's no getting around the fact that more cores = more heat. Expect a relatively low frequency ceiling compared to the Phenom II X4; it'll be surprising if AMD pushes these chips above 3.2GHz; 3.4GHz would likely knock its head on the 140W TDP ceiling.

It's not immediately obvious which Intel processors Thuban will target. Based on what we've seen from our quad-core Nehalem vs. Shanghai match-ups, Intel's ultra-high end, hexa-core Gulftown (Core i9) is virtually certain to pummel Thuban in any head-to-head competition. Knowing this, AMD will likely target Thuban against Intel's Core i7 series, and possibly the upper-end Core i5s as well. In such comparisons, the extra two cores will definitely make a difference. HyperThreading is one of the main reasons the Core i7 takes Phenom II to the mat time after time, particularly in SMP-friendly tests. An extra two cores won't work magic, but it'll put the two processors on much more even ground. AMD could theoretically attempt to press Intel's Core i5/i3 processors with lower-clocked Thubans, but the size and complexity of the die (346mm2, 904 million transistors) make this unlikely. As with Shanghai, Thuban will have to balance itself on a relatively narrow price/performance tightrope.

We could launch into a discussion of how many people actually need six processors, but that horse done been beat before.