AMD announced today that Jim Keller, the veteran engineer who led development of their successful K8 architecture over a decade ago, will be rejoining the company as corporate vice president and chief architect of AMD’s microprocessor cores. He is leaving his post at Apple where he helped lead development of the A4 and A5 system-on-chip used in iOS devices and the Apple TV.

Keller will be reporting to chief technology officer and senior vice president of technology and engineering Mark Papermaster, a former Apple employee himself who left in 2010 after the whole ‘Antennagate’ debacle. Keller’s efforts will be aligned with AMD’s “ambidextrous strategy” developing both high-performance and low-power processor cores that will be the foundation of AMD’s future products.

"Jim is one of the most widely respected and sought-after innovators in the industry and a very strong addition to our engineering team," said Papermaster. "He has contributed to processing innovations that have delivered tremendous compute advances for millions of people all over the world, and we expect that his innovative spirit, low-power design expertise, creativity and drive for success will help us shape our future and fuel our growth."

Indeed, Keller has an impressive resume. He worked at DEC in the 80s and 90s, where he co-architected two generations of Alpha processors. Between 1998 and 1999 he served at AMD and in that short period he co-authored the x86-64 specification, the Hyper-Transport specification and was part of the system engineering team behind the K7, in addition to his aforementioned role on the K8.

Keller also worked at SiByte and Broadcom as chief architect for a line of scalable, MIPS-based network processors that supported 1Gig networking interfaces, PCI and other control functions. In 2004, he moved on to PA Semiconductor, where he led a team that developed a networking system-on-a-chip with an integrated PowerPC processor, and finally he arrived at Apple as part of the PA Semi acquisition in 2008.

Keller’s hiring follows a couple of high profile departures at AMD, including VP of strategy Patrick Moorhead and Product Director Carrell Killebrew back in December. Just last week, Bob Feldstein, the man responsible for brokering deals between AMD and console makers left to work at rival Nvidia, and prior to that in July chip expert John Bruno who worked on AMD's Trinity APUs departed the company for Apple.