In August 2012, Keller returned to AMD, where his primary task was to lead development of new generations of x86-64 and ARM microarchitectures called Zen and K12.

[15][14] After years of being unable to compete with Intel in the high-end CPU market, AMD restored its ability to do just that with the new generation of Zen processors.

[21][22][23] He resigned from Intel in June 2020, officially citing personal reasons,[24] though a later report said his departure was catalyzed by a dispute about whether the company should outsource more of its production.

[27] In 2023, Keller and Sam Zeloof founded Atomic Semi, a foundry tools company that aims to design and manufacture low-cost small scale fabrication equipment.

[28] Jim Keller's wife Bonnie[29] is the sister of Canadian author and clinical psychologist Jordan Peterson.