Back in 1965, Intel founder Gordon Moore famously opined that ongoing advances in chip design would allow engineers to cram ever-greater numbers of transistors onto computer chips—the observation that became known as Moore’s Law. But there’s another passage in his 1965 paper (which you can download here ) that isn’t remembered so well.
After describing the marvels of ever-greater transistor densities, Moore asked, “Will it be possible to remove the heat generated by tens of thousands of components in a single silicon chip?” His not-so-surprising answer: You betcha.
If we could shrink the volume of a standard high-speed digital computer to that required for the components themselves, we would expect it to glow brightly with present power dissipation. But it won’t happen with integrated circuits.
OK, so computer chips aren’t glowing—yet. But heat dissipation may still turn out to be as important to the next 40 years of computer design as Moore’s Law has been since 1965.
That’s what Steve Jobs seems to be thinking in making the switch from IBM to Intel. In explaining that switch, he put up the now-famous Keynote chart comparing the Power PC with Intel’s chips for “performance per watt.” Forget that he failed to define exactly how he was measuring performance. His point was that, no matter how many transistors it’s got, even the speediest chip isn’t much good if it sucks more juice than a daycare center in August.
“As soon as I heard Steve say that the factor where Intel’s road map was superior was processing power per [watt],” Steve Wozniak wrote the New York Times, “I knew right away that it was exactly what I have been reading and saying and so have many others, that this is the real key to the future of high performance computers.”
Sure, switching to Intel means Steve can put “3GHz” and “Power Mac” in the same sentence without looking like he’s getting a migraine. But the main reason for the switch is heat. Faster, more powerful chips mean more power consumption. More power consumption means more heat. More heat means Apple can’t produce ever smaller, ever cooler products. And that makes Steve mad.
Sales of desktop computers are already flattening while laptops are booming. Meanwhile, the iPod is contributing increasingly to Apple revenues.
Five to ten years from now, where will those revenues come from? A tablet Mac? A living room Mac that’s some combination of home entertainment center, video jukebox, personal video recorder? Newton II? Whatever Apple comes up with, chances are it’ll be small and demand cool-running chips of all sorts—which Intel can provide in droves.
So maybe it’s time Moore’s Law got a slight rewrite—call it the Jobs Amendment: Transistor densities will continue to increase, but their temperatures can’t. Power management, as much as megahertz, will be the new frontier of CPU design. And, whatever the other reasons may have been for the switch, Apple’s betting that Intel’s going to beat IBM at that game.