'Pruned' microchips are faster, smaller, more energy-efficient

Mar 16, 2011

An international team of computing experts from the United States, Switzerland and Singapore has created a breakthrough technique for doubling the efficiency of computer chips simply by trimming away the portions that are rarely used.

"I believe this is the first time someone has taken an integrated circuit and said, 'Let's get rid of the part that we don't need,'" said principal investigator Krishna Palem, the Ken and Audrey Kennedy Professor of Computing at Rice University in Houston, who holds a joint appointment at Nanyang Technological University (NTU) in Singapore. "What we've shown is that we can boost performance and cut energy use simultaneously if we prune the unnecessary portions of the digital application-specific integrated circuits that are typically used in hearing aids, cameras and other multimedia devices."

Palem, who heads the Rice-NTU Institute for Sustainable and Applied Infodynamics (ISAID), and his collaborators at Switzerland's Center for Electronics and Microtechnology (CSEM) are unveiling the new pruning technique this week in Grenoble, France, at DATE11, the premier European conference on the design, automation and testing of microelectronics.

Pruning is the latest example of "inexact hardware," the key approach that ISAID is exploring with CSEM to produce the next generation of energy-stingy microchips.

The probabilistic concept is deceptively simple: Slash power demands on microprocessors by allowing them to make mistakes. By cleverly managing the probability of errors and by limiting which calculations produce errors, the designers have found they can simultaneously cut energy demands and boost performance.

At DATE11, Rice graduate student Avinash Lingamneni will describe "probabilistic pruning," the the team created for trimming away the least-used portions of integrated circuits. Lingamneni used the method to create prototype chips at CSEM. The test prototypes contain both traditional circuits and pruned circuits that were produced side by side on the same silicon chip.

"Our initial tests indicate that the pruned circuits will be at least two times faster, consume about half the energy and take up about half the space of the traditional circuits," Lingamneni said. He said he hopes that the system performs even better in the final tests, which are still under way.

Christian Enz, who leads the CSEM arm of the collaboration and is a co-author of the DATE study, said, "The cost for these gains is an 8 percent error magnitude, and to put that into context, we know that many perceptive types of tasks found in vision or hearing applications can easily tolerate error magnitudes of up to 10 percent."

Palem said the next hurdle for "pruning" will be to use the technique to create a complete prototype chip for a specific application. Lingamneni said he hopes to start designing just such a chip for a hearing aid this summer.

"Based on what we already know, we believe probabilistic computing can produce application-specific for hearing aids that can run four to five times longer on a set of batteries than current hearing aids," Palem said. "The collaboration between ISAID and CSEM was key to achieving these results."

Explore further: Using social media for behavioral studies is cheap, fast, but fraught with biases

Related Stories

Indian schools to benefit from new computer chips

Mar 10, 2009

An educational initiative between Rice University computer scientists and Indian educators will enable schools in rural India to be some of the first to benefit from Rice's revolutionary, low-energy computer chips.

Half the productivity, twice the carbon

Oct 11, 2010

Unless the IT industry adopts new energy-efficient technologies in the coming decade, it runs a serious risk of being unable to contribute to growing the global economy if limits are placed on carbon emissions. The findings ...

Recommended for you

Brain inspired data engineering

3 hours ago

What if next-generation ICT systems could be based on the brain's structure and its cognitive and adaptive processes? A groundbreaking paradigm of brain-inspired intelligent ICT architectures is being born.

Forging a photo is easy, but how do you spot a fake?

Nov 21, 2014

Faking photographs is not a new phenomenon. The Cottingley Fairies seemed convincing to some in 1917, just as the images recently broadcast on Russian television, purporting to be satellite images showin ...

User comments : 7

Adjust slider to filter visible comments by rank

Display comments: newest first

that_guy
4 / 5 (1) Mar 16, 2011
Ok, I'll admit, once they listed applications where size, speed, and power usage is extremely critical, but errors can be tolerated (Such as a hearing aid), they made their point. As far as replacing your computer or phone processor, it probably wouldn't do much good, as the rollout time and developing the correct error tolerant software would be eaten up by moores law.
trekgeek1
3.5 / 5 (2) Mar 16, 2011
Ok, I'll admit, once they listed applications where size, speed, and power usage is extremely critical, but errors can be tolerated (Such as a hearing aid), they made their point. As far as replacing your computer or phone processor, it probably wouldn't do much good, as the rollout time and developing the correct error tolerant software would be eaten up by moores law.


Maybe, but a lot of things like audio processing in phones can tolerate errors. Humans aren't really that perceptive when it comes to visual and audio anomalies. Think about the amount of compression we have in audio and video that is nearly unrecognizable in most cases.
Linkin_Atoms
5 / 5 (3) Mar 16, 2011
" 'Let's get rid of the part that we don't need,'..." ... good. Now can we please start doing that with software?
robbor
5 / 5 (1) Mar 17, 2011
what can these scientists do with our government?
SteveL
not rated yet Mar 17, 2011
I know that it is more effecient to engineer and manufacture the same chip millions of times as demand requires. But how is it more effecient to manufacture and then modify chips for specific applications than to simply fab the chips for those same applications?

Applications change all the time - and then you have a useless "tuned" processor. Now, if a chip were manufactured with sections that could be turned on or off via a BIOS as application needed I can see how that would be more useful.
that_guy
not rated yet Mar 17, 2011

Maybe, but a lot of things like audio processing in phones can tolerate errors. Humans aren't really that perceptive when it comes to visual and audio anomalies. Think about the amount of compression we have in audio and video that is nearly unrecognizable in most cases.


Dear Mr. Geek. Please practice critical reading skills. I agreed with the article about things like hearing aids and such, things that rely on processing and compression of audio and video streams. as for general purpose computing, it's a bit more effort to make programs more fault tolerant.
trekgeek1
5 / 5 (1) Mar 17, 2011

Maybe, but a lot of things like audio processing in phones can tolerate errors. Humans aren't really that perceptive when it comes to visual and audio anomalies. Think about the amount of compression we have in audio and video that is nearly unrecognizable in most cases.


Dear Mr. Geek. Please practice critical reading skills. I agreed with the article about things like hearing aids and such, things that rely on processing and compression of audio and video streams. as for general purpose computing, it's a bit more effort to make programs more fault tolerant.


Mr. Geek is my father, just call me Trek. I was just stating that the audio processing chips in phones are not sensitive to errors.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.