The annoying persistence of physical limits

An interesting piece in The Guardian from John Naughton (Professor of the Public Understanding of Technology at the Open University) suggests that those pesky physical limits to growth look like they may be claiming another victim…

For decades Moore’s Law has:

for most people working in the computer industry – or at any rate those younger than 40 – [has] provided the kind of bedrock certainty that Newton’s laws of motion did for mechanical engineers.

The technology of the silicon chip as a driver of processing power may finally be reaching it’s limit – and the limit is physical.

The end of Moore’s Law has been predicted for many years, of course – including by Linus Thorvald back in 2013:

“On the five- to 10-year timeframe scale, I’m very interested to see how the industry actually reacts to the fact that soon we will come against some physical limits,” Torvalds said. “People used to be talking about having thousands of cores on one die because it keeps shrinking, and those people clearly have no idea about physics because we won’t be shrinking for much longer.”

Both physical and financial limits could prevent the frequent doubling in transistor density that was observed by Moore’s Law, he said…

…”In five, 10 years it’s going to be tough,” he continued. “That’s going to affect us in kernel land because we are the layer between hardware and software. What happens when hardware doesn’t improve and magically make us faster? That’s going to be interesting. It might not be five or 10 years, it might be 15, but it’s going to happen.”

Given that Moore’s Law states that ‘the number of transistors in a dense circuit doubles every two years‘ we can see it as another expression of exponential growth running into the inescapable reality of physical limits.

What will have to change is the way software is written:

As Moore’s law reaches the end of its dominion… we basically have only two options. Either we moderate our ambitions or we go back to writing leaner, more efficient code. In other words, back to the future.

Speaking as someone who is interested in the limits of social and technological complexity, the approaching Limits to Moore’s Law should be a wake up call…