CPU Designer Jim Keller Rethinks RISC-V AI Processing at Tenstorrent

September 19, 2023 by Jake Hertz

Hailed for his historic microprocessor designs at AMD, Apple, and Broadcom, Jim Keller is onto his next CPU endeavor at Tenstorrent.

The name Jim Keller carries a lot of weight in the computing world. With a career spanning over four decades, Keller masterminded some of the industry’s most successful projects, including influential microprocessors from AMD and Apple.

Now, Keller is embarking on a new journey as the CEO of Tenstorrent, an AI chip startup designing processing solutions for the cloud and the edge. Keller’s new startup recently announced a fresh injection of funds with a $100M strategic up-round to accomplish its mission. 


Tenstorrent CEO Jim Keller

Tenstorrent CEO Jim Keller accepts a certificate from Samsung Semiconductor Innovation Center, one of the investors from Tenstorrent's recent funding round. Image used courtesy of Tenstorrent

After working as a "chip guru" at tech giants spanning Intel to Tesla, Keller is now channeling his many years of experience to develop processors made of a grid of cores known as Tensix cores. These devices include network communication hardware that "talks" with other processors directly over networks instead of through DRAM. 


A Storied Career in CPU Design

Keller's journey to Tenstorrent began in 1980 when he graduated with an electrical engineering degree from Penn State University. Out of college, he landed a job at Digital Equipment Corporation (DEC) in 1982. There, he was instrumental in developing numerous CPU families, including the VAX 8800, Alpha 21164, and Alpha 21264.


Alpha 21164 microprocessors

Alpha 21164 microprocessors on a Cray T3E-600 processor board. Image (modified) used courtesy of Hannes Grobe & Chresten Wübber, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany/Wikimedia Commons (CC BY-SA 2.5)

Following his time at DEC, Keller transitioned to AMD in 1998, where he served as the lead architect for the Athlon (K7) processor and K8 microarchitecture. Keller's technical expertise then led him to significant roles at several major tech companies, including SiByte, Broadcom, and P.A. Semi. As the chief architect at SiByte and Broadcom, Keller developed MIPS-based processors for 1 Gbps network interfaces and other projects. At P.A. Semi, he served as the vice president of engineering.

One of Keller's most notable stints was at Apple, where he worked on the Apple A4 and A5 SoC mobile processors. These chips powered several generations of Apple's mobile devices and marked a significant milestone in mobile computing.

Keller also held significant roles at Tesla and Intel. At Tesla, he served as the vice president of autopilot hardware engineering, and at Intel, he served as the senior vice president. His work at these companies further solidified his reputation as a leading CPU designer in the semiconductor industry. 


Tenstorrent: A New Chapter in AI Processing

In 2020, Keller made the jump from CPUs to CEO, as Junko Yoshida reported in a biographic piece on Keller. At the helm of Tenstorrent, Keller helped create a new generation of licensable AI computing IP and hardware designed to meet the demands of artificial intelligence workloads.


A Tenstorrent RISC-V 8-core cache coherent cluster.

A Tenstorrent RISC-V 8-core cache coherent cluster. Image used courtesy of Tenstorrent

The company's key offerings include:

  • Grayskull: A family of AI PCIe accelerator cards for high-performance computing (HPC) and data center use cases. These cards range in TDP from 75 W to 300 W and can achieve up to 600 silicon TOPS.
  • Tenstorrent RISC-V: A family of RISC-V processors for AI and server applications. Major offerings in this group include the Ascalon RV64ACDHFMV, the Ascalon Cluser, and the Aegis CPU, which is an Ascalon-based chiplet system architecture. 
  • Tenstorrent AICloud: This cloud-based platform allows users to run AI, ML, and HPC workloads in the cloud. The platform consists of a Grayskull-based computing platform, high-performance storage, and supporting development tools.


Fundraising and the Future

Tenstorrent's recent $100M funding round was led by investors including Hyundai Motor Group, Samsung Catalyst Fund, and several large private equity firms—a testament to Tenstorrent’s rising potential in the industry. According to the company, the new funds will be used to accelerate the development of Tenstorrent's unique technologies, including AI chiplets and an ML software roadmap.