Processing per kiloWatt hour is doubling according to the law laid down by Gordon Moore 50 years ago. And researcher Jonathan Koomey thinks this could help save the world
Using as an example the buying of music at shops, Koomey’s research concludes that downloading music yields 40 to 80 percent reductions compared to buying a CD, taking into account such issues as the network’s energy usage, packaging and production, distribution, travel and a host of other energy consumption factors.
The other two papers – Assessing trends over time in performance, costs and energy use for servers and Assessing trends in the electrical efficiency of computation over time – focus on trends on computing.
Specifically, they deal with both the environmental benefits of increasingly centralised computing resources – data centres and the cloud – and the way that Moore’s Law will play out in future.
In the Servers paper, Koomey argues that cloud computing lowers emissions because of economies of scale. The bigger the data centre the better, from that point of view, but also, the more diverse users are, the better.
For example, if a data centre is owned by one organisation, it will tend to have similar types of user who use its resources at similar times of day, leading to usage peaks and troughs. Troughs mean under-used resources and both wasted capital and energy.
On the other hand, an outsourced data centre – or cloud – that serves many organisations will have users from around the globe. This both helps keep resource utilisation high, and resolves the conundrum that still prevails in many enterprises where facilities pays IT’s ever-growing electricity bill, but the IT department has little or no incentive to reduce it.
In the future trends paper, Koomey sees Moore’s law continuing to operate, even though some have predicted we are five years from the end of the line.
Even current computing technology is very far from the minimum theoretically possible energy used per computation”, he says. “If these trends continue (and we have every reason to believe they will for at least the next five to ten years), this research points towards continuing rapid reductions in the size and power use of mobile computing devices.”
Koomey recognises that “performance could double with the same electricity use. That’s how it works with laptops – battery life is the same but more work is done.
“However, small, battery-driven computation tasks will benefit most as they don’t have exponential growth in requirements.” Koomey says he was talking about controllers and sensors whose autonomy will grow as their computational and energy requirements shrink. In other words, their batteries will last a lot longer.
So Moore’s Law seems safe across multiple technologies – thought it remains to be seen if that will hold true once silicon is superseded.