Software teams full of kids who are just out of school (or just dropped out of school) regularly produce valuable companies. Why should microprocessors be any different? You never hear about a new team successfully making a high-performance microprocessor. Sure, PA Semi had a moderately successful exit, but where did that team come from? They were the SiByte team, which left after SiByte was acquired by Broadcom, and SiByte was composed of key people from DEC who had been working together for over a decade. My old company was similar: an IBM fellow collected the best people he worked with at IBM, became CTO at Dell (back when Dell still did interesting design work), then split off to create a chip startup. A hardware team where most of the people are smart new grads usually spend on the order of $100 million over five or six years only to find that they don't have a competitive product (or, more likely, don't even have anything that's close to working) .

”Smart and gets things done” has become the standard for software hiring, but that isn't even enough for plumbing or carpentry. Next time you have a plumbing emergency, let me know how you pick a plumber. Do you hire the same way you do for software, taking the smart kid who's read a few books, tried out some tools at Home Depot, and is a great hacker? Or do you go with the grizzled veteran with decades of experience?

Physical work isn't the kind of thing you can derive from first principles, no matter how smart you are. Consider South Korea after WWII. Its GDP per capita was lower than Ghana, Kenya, and just barely above the Congo. For various reasons, the new regime didn't have to deal with legacy institutions; and they wanted Korea to become a first-world nation.

The story I've heard is that the government started by subsidizing concrete. After many years making concrete, they wanted to move up the chain and start more complex manufacturing. They eventually got to building ships, because shipping was a critical part of the export economy they wanted to create.

They pulled some of their best business people who had learned skills like management and operations in other manufacturing. Those people knew they didn't have the expertise to build ships themselves, so they contracted it out. They made the choice to work with Scottish firms, because Scotland has a long history of shipbuilding. Makes sense, right?

It didn't work. For historical and geographic reasons, Scotland's shipyards weren't full-sized; they built their ships in two halves and then assembled them. Worked fine for them, because they'd be doing it at scale since the 1800s, and had world renowned expertise by the 1900s. But when the unpracticed Koreans tried to build ships using Scottish plans and detailed step-by-step directions, the result was two ship halves that didn't quite fit together and sunk when assembled.

The Koreans eventually managed to start a shipbuilding industry by hiring foreign companies to come and build ships locally, showing people how it's done. And it took decades to get what we would consider basic manufacturing working smoothly, even though all of the requisite knowledge existed in books, was taught in university courses, and could be had from experts for a small fee.

Today, anyone with a CS 101 background can take Geoffrey Hinton's course on neural networks and deep learning, and start applying state of the art machine learning techniques in production within a couple months. In software land, you can fix minor bugs in real time. If it takes a whole day to run your regression test suite, you consider yourself lucky because it means you're in one of the few environments that takes testing seriously. If the architecture is fundamentally flawed, you pull out your copy of Feathers' “Working Effectively with Legacy Code” and you apply minor fixes until you're done.

This isn't to say that software isn't hard, it's just a different kind of hard: the sort of hard that can be attacked with genius and perseverance, even without experience. But, if you want to build a ship, and you "only" have a decade of experience with carpentry, milling, metalworking, etc., well, good luck. You're going to need it. With a large ship, “minor” fixes can take days or weeks, and a fundamental flaw means that your ship sinks and you've lost half a year of work and tens of millions of dollars. By the time you get to something with the complexity of a modern high-performance microprocessor, a minor bug discovered in production costs three months and five million dollars. A fundamental flaw in the architecture will cost you five years and hundreds of millions of dollars .

Physical mistakes are costly. There's no undo and editing isn't simply a matter of pressing some keys; changes consume real, physical resources. You need enough wisdom and experience to avoid common mistakes entirely – especially the ones that can't be fixed.

CPU internals series