In our first article, we discussed the problems facing CPU scaling and how neither multi-core or heterogeneous many-core designs are a long-term solution. This follow-up addresses what the semiconductor industry is doing about it. It’s a question best answered in two parts: Near-term innovations (think 3-5 years out) and longer-term research initiatives.

Near-term, the ITRS (International Technology Roadmap for Semiconductors) is focused on what’s referred to as “More-than-Moore” (MtM) scaling. The goal of MtM scaling is to extend the same design principles that’ve driven digital device scaling for decades over to analog circuitry, and to integrate those technologies on-die within an SoC/SiP. The goal of MtM scaling is to increase system-level power efficiency and capabilities, provide a coherent, regular roadmap for the relevant technologies, and increase device complexity. The original proposal that laid out the MtM concept states “it is the heterogeneous integration of digital and non-digital functionalities into compact systems that will be the key driver for a wide variety of application fields, such as communication, automotive, environmental control, healthcare, security and entertainment.”

A recent article at the New York Times discussing the use of medical devices capable of interfacing with a mobile phone is a timely example of exactly the sort of integration More Than Moore is meant to address. Instead of focusing strictly on the CPU as the enabler of experiences, MtM emphasizes integration and efficiently designing every component. As the MtM paper states, “Whereas More Moore may be viewed as the brain of an intelligent compact system, ‘More-than-Moore’ refers to its capabilities to interact with the outside world and the users.”

The original MtM proposition didn’t discuss converting analog circuits to digital ones, but Intel’s recent description of a fully digital radio in an ISSCC 2012 paper is another demonstration of the theory. Existing smartphone radios have digital basebands but rely on analog circuits for most other components. Analog transistors are more difficult to scale than their digital counterparts, which is part of why a true digital radio makes sense. Intel’s paper claims it’s possible to effectively shield the CPU and radio from interfering with each other — previously, this obstacle would’ve prevented such a combination.

One of the most striking characteristics of current semiconductor research is how completely the search for lower-power devices has subsumed the old clockspeed obsession. 0W has become the new 1GHz; success is measured in how long your chip spends in its lowest-possible power mode and how quickly it transitions. Performance, the old God of Computing is now merely an efficient means to achieve the lowest possible minimal power usage.

Intel’s research into digital radio and Near Threshold Voltage (NTV), Samsung’s PenTile displays, which use an RG-BG subpixel configuration rather than the conventional RGB-RGB stripe, 3D chip stacking, and increased SoC integration are all examples of how industry focus has shifted to a device-centric viewpoint. The work in this area, however, isn’t limited to mobile hardware. The K supercomputer, designed by Fujutsi and Riken, was fine-tuned for power efficiency by matching power supply output to the optimal voltage requirements of each physical CPU. The research team estimates that this saved ~1MW of power and reduced operating costs by ~$1M USD per year.

Futjitsu’s approach may never translate directly to the PC or mobile industries, but it’s indicative of how manufacturers are looking in non-typical areas to find ways to reduce power consumption and improve efficiency. It dovetails with research projects into improving multi-core and many-core designs and ties to features as diverse as Intel’s TSX extensions in Haswell and the idea of implementing programs directly in hardware as a way to leverage increased transistor counts.

These are the sorts of projects and initiatives we expect to dominate device cycles for the next 3-5 years. Past that point, the situation changes.

Next page: The long-term picture