Clever timing makes computers produce less heat—even below Landauer's limit

January 29, 2019, University of Twente
Computer operations producing heat, influencing other parts of the circuit as well. Using clever timing, the energy cost can be reduced. Credit: University of Twente

Computer systems produce a lot of heat. Data centers are full of buzzing cooling fans, and even smartphones can heat up with high use. Reducing energy consumption is one of the main challenges in information technology. But there is a theoretical, temperature-dependent lower limit to cooling, as stated by Rolf Landauer in the 1960s. Jan Klaers of UT now shows that by cleverly timing the interaction of heat and logical operations, it is possible to go even lower than this limit. This new theory, presented in Physical Review Letters, may lead to increasingly energy-efficient electronics.

Long before the large-scale introduction of , in 1961, Rolf Landauer (1927-1999) published his famous article about the minimum amount of needed to erase one bit of information, that is, changing it from the "one" state to the "zero" state. This minimum, according to Landauer's Erasure Principle, is temperature-dependent, and connects the laws of thermodynamics and information theory.

Many years later, in 2012, experiments published in Nature confirmed the principle. For the current generation of computers, this lower limit has not yet been reached; typical of a logical operation is still about 1,000 times higher. But this will certainly change in the coming decades. Will computing then reach a fundamental limit? In his paper, Jan Klaers proposes a way of reducing by synchronizing computer operations and temperature in a smart way. With this technique, it will be possible to lower the energy needed for erasure below the Landauer limit.

Operating when cold

Considering the many that take place in a computer, the temperature profile is complex. If one bit changes state at a certain logical gate, the will occur in the surrounding gates, as well. Although complex, temperature and energy consumption have the same rhythm as the clock of the microprocessor. These are called squeezed thermal states, and they can be observed during computer operation. This means that at certain times, the temperature and energy costs are lower for the same operations. Synchronizing the logical operations with these moments in which the temperature is effectively colder will lead to energy consumption lower than the Landauer limit.

Klaers analyzed a minimalist mechanical model representing a one-bit memory resembling the one Landauer used for his theory. Further research will have to show what results can be achieved in actual computer systems.

Dr. Jan Klaers is a researcher of the Complex Photonic Systems group, part of UT's MESA+ Institute. Within the group, he started his own research direction in the field of experimental quantum thermodynamics.

Explore further: Computing study refutes famous claim that 'information is physical'

More information: Jan Klaers. Landauer's Erasure Principle in a Squeezed Thermal Memory, Physical Review Letters (2019). DOI: 10.1103/PhysRevLett.122.040602 , https://arxiv.org/abs/1809.02429

Antoine Bérut et al. Experimental verification of Landauer's principle linking information and thermodynamics, Nature (2012). DOI: 10.1038/nature10872

Related Stories

Cooler computing through statistical physics?

June 20, 2018

In the space inside a computer chip, where electricity becomes information, there's a scientific frontier. The same frontier can be found inside a cell, where information instead takes the form of chemical concentrations. ...

The astonishing efficiency of life

November 17, 2017

All life on earth performs computations – and all computations require energy. From single-celled amoeba to multicellular organisms like humans, one of the most basic biological computations common across life is translation: ...

Recommended for you

CMS gets first result using largest-ever LHC data sample

February 15, 2019

Just under three months after the final proton–proton collisions from the Large Hadron Collider (LHC)'s second run (Run 2), the CMS collaboration has submitted its first paper based on the full LHC dataset collected in ...

Gravitational waves will settle cosmic conundrum

February 14, 2019

Measurements of gravitational waves from approximately 50 binary neutron stars over the next decade will definitively resolve an intense debate about how quickly our universe is expanding, according to findings from an international ...

0 comments

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.