• Dirk Meyer - K7 chief architect

Citiraj:

Citiraj: The new processor was jointly developed by Meyer's team in Austin (Texas) and Fred Weber's team in Sunnyvale (California).

• Jim Keller - K8 lead architect

Citiraj:

Citiraj: Jim was lead architect on the first K8 project (the first iteration of K8 was eventually canceled and Fred Weber became lead architect on the design that came to market). Citiraj: “He’s the Forrest Gump of our industry,” says Fred Weber, former chief technology officer of AMD. “He keeps being in the middle of the interesting stuff and making a difference.” It was a team-building exercise, but also an expression of frustration at Keller’s departure, says Fred Weber, AMD’s chief technology officer at the time. “I would never say he doesn’t finish things—he absolutely does—but he leaves earlier than most.” Citiraj: It was unusual for a designer to leave so early in a chip’s development, and some of Keller’s AMD team were disappointed with his decision. Afterward, the crew returned to their office and decided to remove a wall separating engineers from others on the team—on the spot, that night, with sledgehammers. The K8 eventually came out in 2003. The chip was officially named Opteron—but AMD marketed one version as Sledgehammer. Citiraj: From 2012 to 2015, he returned to AMD to work on the AMD K12 and Zen microarchitectures. Citiraj: Jim Keller will serve as a vice president and the company's Chief Architect for CPU Cores. Citiraj: Chip manufacturers’ continual advances were making chips faster and more powerful, but they were also creating new problems. The fastest chips now often came very close to overheating, putting a ceiling on how much faster they could perform. Keller had spotted a new technical advance that could help address the problem—chiplets. Citiraj: Jim’s goal was to build the team and lay the groundwork for the new microarchitecture, which for the long-term will revolve around AMD Processor Architect Michael (Mike) Clark. Former Intel engineer Sam Naffziger, who was already working with AMD when the Zen team was put together, worked in tandem with the Carrizo and Zen teams on building internal metrics to assist with power as well. Mark Papermaster, CTO, has stated that over 300 dedicated engineers and two million man-hours have been put into Zen since its inception.

• Jim Keller - involved in designing Apple A4/A5 processors

Citiraj:

Citiraj: Keller remained restless for the next interesting problem. In 2004, he joined another Dobberpuhl startup called P.A. Semi that focused on chips for high-end PCs and servers. And in 2008 he jumped to Apple (just before Apple acquired P.A. Semi). The preponderance of evidence points to an Intrinsity designed ARM Cortex-A8 core. This had more to do with the existing relationship between Samsung and Intrinsity just look at the timing. The acquisition of Intrinsity does, however, draw a line in the sand that may well be ahead of any Intrinsity re-designed Cortex-A9 appearing, leaving only Apple with access to Intrinsity for the multi-core generation. What about PA Semi? The A4 certainly does not appear to have much influence from PA Semi, at least at the block level. Some designers were no doubt involved in the A4, but definitely not to the point of a wholesale CPU design. The team was likely involved in other blocks or just applying their expertise to help pull together a complex SoC design. Steve Jobs described the PA Semi acquisition as part of Apple's strategy of product differentiation. Citiraj: Keller joined a team tasked with designing Apple’s own line of chips. Starting with the iPhone 4, the phones used designs Keller had worked on. He had his greatest impact on Apple’s A6 and A7 chips, which powered the iPhone 5 and 5s. The designs weren’t just faster than those of competitors: Apple optimized the chips for smoother graphics, making iPhone rivals seem janky by comparison. The chips also accelerated the iPhone’s speech processing—just in time to power Apple’s new Siri digital assistant. Citiraj: The lead designer behind Apple’s custom A-series chips A7-A12X, Gerard Williams III, has left the company. Gerard Williams III was the senior director in platform architecture at Apple. He worked at the company for 9 years. Apart from the chip design, Williams also oversaw the layout of various other parts on the SoC. Before Apple, Williams worked at ARM for 12 years. He was the technical lead on Arm’s Cortex-A8 microarchitecture which made its way into the iPhone 3GS and numerous other Android devices. His name is listed in over 60 Apple patents as an inventor. Apple has been moving the development of key chips used inside its devices in-house. What first started as the A7 chip featuring a 64-bit microarchitecture with the iPhone 5s has now expanded to include a custom GPU, a Secure Enclave chip, W1/H1 wireless chips, and more. Apple is also expected to switch to its custom-designed PMIC (power management IC) in the future to further improve iPhone battery life.

• Jim Keller - joined Tesla as Vice President of Autopilot Hardware Engineering

Citiraj:

Citiraj: At Tesla’s Autonomy Day event for investors on Monday, CEO Elon Musk made a characteristically big deal out of the company’s new microchips. Describing the new FSD computer (it stands for “full self-driving”) that will power Tesla’s vehicles, Musk said they contained what was “objectively” the “best chip in the world.” And that’s not best by a little, but “by a huge margin.” Pete Bannon, the company’s lead on the project and Tesla’s head of Autopilot hardware, opened the event with a detailed rundown of the FSD’s technical specs. Musk was sitting beside him as the hype man, ready to translate technical specs into sound bites and boasts. Bannon is a respected figure in the industry, with stints designing chips at Intel and Apple before he joined Tesla in 2016. He explained that the FSD computer will be the brain of Tesla’s cars, processing input from eight cameras, 12 ultrasonic sensors, a front-facing radar, and GPS and mapping data. This data will be used to steer the car on the road.

• Mike Butler - Bulldozer chief architect

Citiraj:

Citiraj: The Bulldozer architecture is arguably AMD's first radically new architecture since the introduction of the K7 Athlons way back in 1999. Both K8, which added 64-bit and integrated the memory controller, and K10, which added single-chip quad core, more cache, and a host of changes to improve instructions per cycle (IPC), can trace their lineage back to the K7. Bulldozer is something new. For Bulldozer specifically, additional design influences came into play. In the words of Chief Architect Mike Butler, AMD's goal was to "hold the line" on IPC (presumably meaning to keep it at around the same level as in Phenom II) but to increase the clock speed, thereby achieving improved single-threaded performance, too. The processor also had to be power efficient. Taken together, these goals explain just about every aspect of Bulldozer's design.

• Michael Clark - Zen lead architect

Citiraj:

Citiraj: Zen was picked by Michael Clark, AMD's senior fellow and lead architect. Citiraj: Zen 4 was first mentioned by Forrest Norrod during AMD's EPYC One Year Anniversary webinar held on November 6, 2018. Citiraj: Zen 5 was first mentioned by lead architect Michael Clark during a discussion on April 9th, 2018.