(Bloomberg Opinion) — What was already a tough week for Intel Corp. got worse Thursday night: One of the chip giant’s most essential employees left the building.Intel announced top chip architect Jim Keller resigned effective immediately for personal reasons after only two years on the job. The company didn’t specify exactly why but added the executive would serve as a consultant for six months to help with the leadership transition.Keller’s departure is a big deal. No one else in the semiconductor industry has his pedigree of chip-engineering success over the last two decades. In the late 1990s, he designed Digital Equipment’s Alpha chip, which was the fastest in the world at the time. Then, after stints as lead chip architect at Advanced Micro Devices Inc. and PA Semi, he led the team at Apple Inc. that created the A4 and A5 mobile processors, which were instrumental to the success of the early iPhones. After Apple, he returned to AMD and helped design the Zen microarchitecture, laying the groundwork for the company’s turnaround. And prior to joining Intel in 2018, the executive was the head of Tesla Inc.’s Autopilot efforts.The surprising resignation came after other momentous news for Intel earlier this week. On Tuesday, Bloomberg News reported that Apple was on the verge of announcing plans to use its own chips over Intel’s in Macs starting next year. That day I wrote about how Apple’s move would have multiple negative ramifications for Intel’s chip business. But the Keller announcement may be even more worrisome for Intel’s long -term future.When Keller arrived at Intel, his reputation reassured investors that the chipmaker would improve upon its lackluster technology execution in recent years. The vertically integrated company, which manufactures and designs its own chips, had fallen behind on both fronts. First, Taiwan Semiconductor Manufacturing Co. surpassed Intel in its capabilities to manufacture chips at smaller, more advanced semiconductor processes. Second, AMD’s latest chip designs have proven to offer better performance, along with lower energy consumption, spurring the beginning of market-share losses for Intel. According to Mercury Research, AMD has wrested nearly 2 percentage points of desktop PC processor share from Intel over the last year.In another sign of the sea change in technical prowess, last month Nvidia Corp. decided to choose an AMD server processor for its latest artificial intelligence computer. It marked the first time Nvidia didn’t choose Intel for its AI system, and it is especially noteworthy because AMD is Nvidia’s primary competitor in the graphics semiconductor space. Nvidia said it went with AMD because of its better performance.The next few years will be critical as chipmakers jockey for position in dynamic markets from cloud computing to AI, autonomous cars to visual graphics computing. With Intel’s current lineup falling behind, Keller’s resignation couldn’t come at a worse time.Industry analysts say it takes about four years for a chip architect to truly make its mark on a product pipeline. That makes Keller’s short tenure particularly problematic. Intel needed his experienced hand to guide the final stages of development for its next generation of chips. It simply can’t afford to lose him now.This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.Tae Kim is a Bloomberg Opinion columnist covering technology. He previously covered technology for Barron’s, following an earlier career as an equity analyst.For more articles like this, please visit us at bloomberg.com/opinionSubscribe now to stay ahead with the most trusted business news source.©2020 Bloomberg L.P.