According to chip designer Jim Keller, AMD pulled the plug on the development of its own Arm cores after he left the company. He calls that a stupid decision. Around 2014, AMD had plans for server processors based on Arm cores and the plan to create its own Arm cores.
Keller worked at AMD on the first, second and third generation Zen cores. He recently told a conference that he noted at the time that the cache design for Arm and x86 CPUs is largely the same, as are many other parts. The difference in the processor architectures is mainly in the decoder unit.
Because of the similarities, Keller’s team began work on its own Arm core codenamed K12. AMD had purchased a license from Arm for this. “They stupidly canceled that project,” says Keller in his Future of Compute presentation. According to Keller, “certain executives” at AMD scrapped the project after his departure because they were “afraid of change.”
AMD planned to use Arm cores for server processors, also in combination with x86 processors. In 2014, the processor maker presented plans for server processors based on existing Arm cores. The own Arm cores were also put on the roadmap for 2016. That was later postponed to 2017, but it never came to that. A year after the presentation, AMD scrapped the Arm plans.
Instead of Arm cores, AMD now uses x86 cores based on the Zen architecture in its EPYC server processors. The manufacturer is currently having great success with this. EPYC processors are currently found in the fastest supercomputer in the world. Five out of the ten fastest systems in the top 500 supercomputer list feature EPYC processors.
K12 project from AMD
Keller worked at AMD, Intel, Apple, Tesla and more
Jim Keller has a long track record as one of the foremost designers of microarchitectures for processors. He worked at DEC on Alpha processors in the 1980s and went to AMD in 1998 to work on the Athlon processors. A year later, he left for SiByte to work on MIPS processors. That company was acquired by Broadcom. As of 2004, Keller held a top position at PA Semi, the company Apple acquired in 2008 to make its own socs for iPhones.
Keller worked at Apple until 2012, then returned to AMD, where he worked on the Zen architecture and the K12 project for Arm processors. In 2016, he joined Tesla to work on AI chips for the Autopilot hardware. In 2018 he made the switch to Intel, where he left again in 2020. Keller is currently the CTO of Tenstorrent, a start-up working on AI chips.