You worked on the design and development of the 386 but then became the chief architect for the 486 at the age of 25. What was that like?
The 486 was my baby from beginning to end. It was frightening yet exhilarating at the same time. I had only a couple of years of experience, having just finished my degree at Stanford, and I was put in charge of what would be the most important project in the industry at the time. There were 100-plus people in the program, some of them 25 years my senior.
What is the "software spiral"?
The day before we introduced the 80486 [on April 10, 1989], we already had billions of dollars worth of software waiting to run on the chip. When we introduced it, [Intel CEO] Andy Grove made this powerful statement about the "software spiral."
The idea of the spiral was, we'd introduce hardware that was faster than the software and then allow the software to catch up, which requires the hardware to jump ahead again. So software begets hardware, hardware enables software, and that spiral is really what's been driving the industry for many, many years.
It seems that that concept still holds, with multicore chips now available but without a lot of software that can run on more than one processor at a time.
Exactly. I'd say we have made a new turn in the spiral, which is the move to multicore.
When did Intel realize that the game was up for processor clock-speed improvements and that the future lay in multicore processors?
I was chief technology officer for Intel in 2001, and I published a paper that became known as "the power wall" paper. It had this graph, which became famous, that plotted the thermal density — how much power we were trying to squeeze into a given area of silicon — and it showed that our chips would have the thermal density equal to a nuclear reactor or to the surface of the sun. It showed that the trajectory we were on was not sustainable. We needed to make what became known inside Intel as the right-hand turn.
There were huge debates internally over the data — whether we could continue on the curve we were on, whether there were cooling systems that would allow us to continue and so on. And people said, "Hey, if we aren't in the gigahertz race, where are we? Our competition will build gigahertz chips, and the market has been conditioned to see that as a better chip." So there were technical reasons and market reasons why there was tremendous resistance to the argument.
What does the future hold for the x86?
I gave a speech at the Intel Developer Forum in Shanghai [in April]. I included a picture of the Monkey King, which in China had a very powerful tool — the golden stick. It could be as small as a needle or as big as a pillar that held up the sky.
In my speech, "From Milli Watts to Peta FLOPS," I made the analogy that, like the Monkey King that had the golden stick, we had the architecture that will grow up to be the biggest things on Earth — petaflops computers — and also the smallest computers on earth.
Read more:
- Happy birthday, x86! An industry standard turns 30
- What's next for the x86?
- Timeline: A brief history of the x86 microprocessor
- Q&A: Patrick Gelsinger, x86 pioneer