Analysis: The greening of silicon valley

One of the world's centres of innovation is leading the adoption of environmentally friendly technologies.

Silicon valley is greening over as a combination of the strengthening evidence for global warming, the industry's recognition of the part its products play, and the realisation that there may be money to be made tackling the issue, hits home.

Several speakers at this year's Globalpress Electronics Summit highlighted just how much of the world's energy consumption now goes into driving electronic equipment, and the social consequences of that.

"Excess energy consumption equals trouble, because it is bad for the environment and may turn out to be equally bad for the economy," said John East, CEO of programmable logic company Actel. "It does no good to anyone that the US needs so much oil that it has to come from other countries."

Industry responsibility

East said that roughly half the problem of global warming emissions comes from cars and half from generating power. About half of electrical power goes on electric motors, with the other large consumers being communications and computing systems. "Those three things are the key," he said. "Tackle those and we can beat the problem."

Chris Rowen, CEO of processor core company Tensilica, agreed that it was time for the electronics industry to take responsibility for its products.

"The role of electronics in modern society is now so broad and so deep that it is taking on a very different aspect," he said. Rowen estimates that electronics accounts for 6 per cent of the US's electricity consumption, or 200TWh per year, which is equivalent to the output of 30 power stations, 150 megatonnes [Mt] of CO2 or 30 million cars on the road.

East argues that there is not much hope that alternative energy sources could solve the consumption problem in the short-term. "Growing corn is terrifically wasteful of energy," he said. "It takes three units of energy to produce four units of corn power - most of what you gain is wasted."

He's not much more of an enthusiast for hydrogen power in cars, pointing out that a lot of it is produced using electricity generated by burning fossil fuels. He's equivocal about nuclear power, although does believe that when the US largely shut down its nuclear build programme about 20 years ago, "we did ourselves a disservice because of the greenhouse gases subsequently released to contribute to global warming.

"The best option is solar. I think solar will go through a Moore's Law improvement process just like the semiconductor industry has".

East has installed a 6kW solar system on the roof of his house and is putting a 200kW system on Actel's roof, but says more must be done. "It will be decades before we can build enough solar power to solve the problem we face. Wind power is good but a long way from providing most of our needs. If we're waiting for better generating technologies then we are going to be in trouble."

Both East and Rowen believe that they can adapt their products to tackle the power efficiency issue, despite problems with the increasing power consumption of deep submicron IC manufacturing processes.

"We've been spending a fortune on reducing power in our devices," said East.

"There was a long time when people didn't care about power, but I know I see a change. We're all ashamed to be contributing to the problem, and are beginning to face legislation requiring us to be more power conscious.

"One thing I do see is the solar uptake in the Valley. Google has covered parking lots that carry solar arrays. And people are fitting solar systems to their houses. They're seeing that they have the chance to go do something.

"Can we solve the problem with silicon? No. But it is a big enough piece of the problem that we had better be working on it."


East says the 200kW solar array he is having installed at Actel will cost millions of dollars and will "kind of break even". But he also compares that effort with the work the company has done to cut the power in its chips.

"If a typical Actel part draws one-tenth of a watt less than equivalent parts from our competitors, and we sell four million chips a quarter, then each quarter we are doing about twice as much good by shipping the parts as by buying the solar installation," said East.

Rowen points out that expecting to reduce chip power consumption through denser manufacturing processes is something of a lost cause.

"Over the next factor of ten decrease in size of the basic transistors in a design, we will only see a very small change in power use," said Rowen. "One way to fix this is to go parallel, because by splitting up a job, for example on to two processor cores each running more slowly, you can get a quarter the power.

"We have another tool available to us," he added. "As you put more cores into a design you have the opportunity to specialise their functions, which could give a better than linear improvement in performance per unit of power consumed.

"What you get from the combination of multiple cores and specialised processors is an energy breakthrough. This means longer battery lives and more mobility, simpler packaging, reduced product and operating costs and lower environmental impact," he said.

Rowen argues that tailoring the instruction set of a custom microprocessor to a particular use can lead to four-fold gains in power efficiency in audio applications, and up to a 25-fold energy efficiency gain for video processing.

Server farms

Tom Trill, senior director of marketing at memory company Qimonda, pointed out that the server farms that run so much of ecommerce and online search are now a major consumer of power - one estimate in 2005 suggested that 1.2 per cent of US electricity consumption came from server farms.

Trill said that the actual servers took about 25 per cent of the systems power budget and energy costs of running data farms. "You can reduce the energy used by about 20 per cent,' he said, "making a saving of $300m in the $7.2bn it cost in 2005 to run the world's data farms. There is a power culture in which our dependency on inefficient silicon is similar to our dependency on oil - there are alternatives but adoption is slow."

But it is likely to be a combination of techniques, such as better manufacturing processes, parallel execution, better system and software design, improved memory architectures and subtle circuit design that will be necessary to tackle the power consumption issue at the chip and the global level.

"Engineers today have got to start thinking about very small changes that can make a big difference," said Rick Zarr, worldwide partnership marketing manager for National Semiconductor.

Setting the issue back into a wider context, Rowen said that the increase in GDP per head that goes with improving national prosperity for any country usually goes hand in hand with an increase in CO2 production per head.

"We believe that by applying these improvements in energy efficiency in the electronics industry we can do better than this. I think we should embrace the vision both to grow GDP per head and do it in an energy-efficient way."

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