'Defective' chips could power efficient smartphones

Smartphone chip makers may be trying too hard to produce high quality chips, according to researchers who believe that some dodgy processors could actually benefit handsets.

The likes of Qualcomm, Samsung or Intel might pride themselves on the churning out reliable chips to support the boom in smartphones, but it might not always be necessary.

According to researchers at the École Polytechnique Fédérale de Lausanne, it is possible to use defective chips and still attain the high levels of performance that are demanded by users.

The EPFL researchers say that manufacturers usually won’t make chips that run at very low voltages and are energy efficient because this would lead to low yields, and because many of these chips would be unusable after production.

But rather than chucking chips that are less than A-grade into the bin, Andreas Burg at EPFL says that a new technique could allow them to make their way into handsets.

Burg’s team developed a simulation system that allowed hardware failures to be tested.  The results showed that it was possible for chip systems to tolerate a large number of cock ups on the circuit and still function reasonably well.

Burg says that, in fact, ‘bad’ chips were more energy efficient as they were able to reduce power consumption by “performing very aggressive voltage scaling”, beyond what is usually possible.

Basically, the technique is similar to that of wireless communications n smartphones, which can function without all relevant data being sent in one piece. Electronic devices are resilient to these distortion in signals, and can still load a web page even if all of the information does not arrive in one go.  

Burg took the same approach to chip design, with the system continuing to function even if data is lost or distorted.

Chips could use the ability to function with a reduced power supply, albeit with a slowed ability to perform certain functions, but the chips would still be able maintain overall abilities while taking less drain on the battery.

If chips were able to switch into this mode then it would mean customers would have access to cheaper processors, and consequently, cheaper handsets.

Of course, whether consumers or vendors hungry for the latest and greatest hardware would be happy to see bargain basement chips hit the market is unclear, but there could certainly be applications where this would be useful.

Some, like ARM, are already working on chip designs that switch between lower power cores when completing less intensive tasks.

While we don’t expect an ARM value range hitting the shops soon, perhaps Burg’s technique is well suited to the requirements of emerging markets.