Feeds

Researchers propose ‘overclock’ scheme for mobiles

Processing at a sprint to overcome tech limitations

Seven Steps to Software Security

It’s getting increasingly difficult to pack enough processing power into mobile phone form factors, so US researchers are proposing a new scheme: seriously over-spec the processors, but only use their power when it’s needed.

The research paper, authored by scientists from the Universities of Pennsylvania and Michigan, suggests a scheme called “computational sprinting” – build mobile chips not with a couple of cores working hard all the time, but with as many as 16 cores, most of which are idle unless they’re needed.

The paper’s authors say that future smartphone development is running into a dual problem: shedding heat, and preserving battery life. While we’re not yet at the limit of transistor density, they say that “voltage scaling has stalled”.

For much of the history of the integrated circuit, smaller geometries that allow more transistors to be packed into less space are accompanied with lower operating voltage, which helps designers cope with the job of getting rid of the heat generated by all those extra transistors.

Without that, power density increases from one generation of processor to the next and in mobile devices, power (and cooling) rather than chip real estate becomes the barrier to higher performance.

Hence the “computational sprinting” described by the researchers. Their analysis looks at a system that spends most of its time operating a single core with 1W peak power, since most smartphones spend most of their time doing not very much. The system could, however, “burst up” to use all of its cores when necessary.

This, the paper states, is representative of the user experience with smart phones: “short bursts of intense computation punctuated by long idle periods waiting for user input” (El Reg: sounds like a quotation about war, for which I can’t find a good citation right now).

The whole chip could be fired up for the computationally-intensive task, even though this would momentarily exceed the power budget and heat dissipation capabilities of the device, because there’s a time lag between powering-up the processor cores and the extra heat generated. This “thermal capacitance” (also used by burst systems like Intel’s Turbo Boost technology), combined with usually “dark” silicon, could “result in an intense sprint with the potential to provide an order of magnitude improvement in responsiveness”, the authors state.

The paper, by Arun Raghavan and Milo Martin (University of Pennsylvania), and the University of Michigan’s Yixin Luo, Anuj Chandawalla, Marios Papaefthymiou, Kevin Pipe, Thomas Wenisch, was prepared for the 18th Symposium on High Performance Computer Architecture, and is available here. ®

The smart choice: opportunity from uncertainty

More from The Register

next story
Auntie remains MYSTIFIED by that weekend BBC iPlayer and website outage
Still doing 'forensics' on the caching layer – Beeb digi wonk
Apple orders huge MOUNTAIN of 80 MILLION 'Air' iPhone 6s
Bigger, harder trouser bulges foretold for fanbois
GoTenna: How does this 'magic' work?
An ideal product if you believe the Earth is flat
Telstra to KILL 2G network by end of 2016
GSM now stands for Grave-Seeking-Mobile network
Yorkshire cops fail to grasp principle behind BT Fon Wi-Fi network
'Prevent people that are passing by to hook up to your network', pleads plod
Seeking LTE expert to insert small cells into BT customers' places
Is this the first step to a FON-a-like 4G network?
BlackBerry: Toss the server, mate... BES is in the CLOUD now
BlackBerry Enterprise Services takes aim at SMEs - but there's a catch
prev story

Whitepapers

Top three mobile application threats
Prevent sensitive data leakage over insecure channels or stolen mobile devices.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
Build a business case: developing custom apps
Learn how to maximize the value of custom applications by accelerating and simplifying their development.