Backwards Compatility with AM3 is the Big Surprise

Eat that Gulftown: AMD officials have not only confirmed that it will release a hexa-core processor next year – but it will be backwards compatible with existing AM3 and AM2+ motherboards.

Although heavily reported as a rumor that an AMD six-core was coming to consumer desktops, the company had not confirmed rumors. That is until Monday, when AMD officials told Maximum PC that the chip was a done deal.

“We are all about platform longevity and long-lived upgrade paths,” and AMD spokesman said in a sideways ding at its competitor Intel which has a penchant for requiring new sockets for its CPUs. Intel currently has three different socket infrastructures on its desktop computers – all incompatible. The confirmation also comes one day before Intel’s three-day IDF conference which usually blots out all news from competitors for days.

AMD’s chip is codenamed Thuban and will feature all six cores on single 45nm die. Thuban will feature an integrated DDR3 controller. The company didn’t confirm branding but the chip is expected to be labeled as the Phenom II X6. The chip is derivative of the six-core Opteron chip which made its earlier this summer.

Extrapolating from the hexa-core Opteron, Thuban is likely to be a 346mm2 chip and have a massive 904 million transistors. As a comparison, Intel’s Core i7-975 Extreme Editions have 731 million transistors on a 262mm2 die, the Core i5-750 has 774 million transistors with 296mm2 die and the Phenom II X4 965 Black Edition 758 million transistors on a 258mm2 die.

The chip is expected to have 3MB of L2 and 6MB of L3 cache. The company did not specific initial clock speeds but they are not expected to be as high as the quad-core parts. That’s likely due to added thermal output from the two additional cores.

Thuban is not due until sometime next year and is unlikely to beat Intel’s Gulftown to stores shelves. Intel’s Gulftown, likely to be called Core i9, when it is released, will slip into existing LGA1366 boards and will offer 12-threads to the OS with six of those coming from cores, and the other six from HyperThreading.