Multi-core magic
As mobiles race to beat the capabilities of computers, it is inevitable that some of the trends in the PC processor space will also spill over to the mobile world. One such trend is the magic of multi-cores.
“Due to the growth in the availability of high-speed mobile and WiFi networks, mobile devices will also be used for various performance-intensive tasks that were previously handled by traditional PCs. Single-core mobile processors are not designed to deal with this tidal wave of high-performance use cases,” explains Dhupar.
“On a mobile processor that has a multi-core CPU, multi-tasking can be shared between the distinct processing cores. Hence, as the performance requirements of mobile applications increase, SoC vendors are adopting multi-core processor architectures to deliver the increased performance and keep power consumption within mobile budgets,” he adds.
It is a common misconception that more cores mean higher power consumption. In fact, multi-core CPUs are able to distribute their workload across their cores so that each CPU core can run at a lower frequency and voltage. This means each core consumes significantlylower power and offers much higher performance per watt than single-core CPUs.
The performance of a smart phone has increased 40 times over the last ten years; and the increase in performance since 2008 alone has been eight times. One reason for this is the adoption of multi-core technology. Last year saw the launch of dual-core Cortex-A9 smartphones. This year, we are likely to see the launch of quad-core Cortex-A9 smartphones.
Bruce predicts that at the end of 2012, we will see the launch of Cortex-A15 handsets with a 50 per cent increase in performance. “Also in 2012 you will see the launch of Cortex-A15 based handsets at a $100 price point. The Cortex-A15 processor allows $100 smartphones to deliver the user experience of a $500 smartphone in 2010,” he says.
NVIDIA is also focusing on multi-core architectures. Its latest Tegra 3 processor goes a step beyond quadcore by adding a fifth‘companion’ core. Its internal architecture is identical to the four main Cortex-A9 CPU cores but the fifthcore is built using a special low-power silicon process. Using a technology called variable symmetric multiprocessing, the fift core handles low-frequency tasks such as those common in active standby mode (Twitter and Facebook updates, e-mail synchronisation, etc) and applications that do not require significantCPU processing power, such as audio streaming, offline audio playback, an both online and offine video playback.
When more demanding tasks are required, the other four cores can be called upon. This approach allows Tegra 3 to deliver significantlylower power than competing mobile processors at all performance levels.
It is interesting to note that the popular low-cost, open mobile software development platform PandaBoard too is now available in a dual-core version, keeping pace with the current trend. In November 2011, the community announced the availability of the PandaBoard ES based on TI’s OMAP4460 processor, whose multi-core architecture includes two ARM Cortex-A9 cores running at up to 1.2 GHz each, delivering a 20 per cent increase in overall performance and a 25 per cent increase in graphics when compared to the OMAP4430 processor used by the earlier PandaBoard.
Looking ahead
Dhupar feels that with mobility becoming more sophisticated, the number of CPU cores in a mobile processor will continue to multiply. Quad-core CPUs will enable mobile devices to further push the performance envelope and allow application and game developers to deliver new mobile experiences, all while extending the battery life.
Dhupar expects Windows on ARM platform becoming a reality some time late this year or next year.
Joshi sums up, “The rapid increase in consumer demand for multimedia, gaming, etc on mobile devices will drive computing speed. Aside from that, low power consumptions, size and weight are key improvements to foresee.”
The author is a technically-qualified freelance writer, editor and hands-on mom based in Chennai
