ARM and Symbian today announced Symbian OS would support the ARM Symmetric Multi-processor (SMP) architecture in future OS versions. This technology allows for multiple CPU cores to be used in mobile phones. Don't get too excited though, the first phones using multiple core processors are not expected before 2010. In other Symbian related processor news Renesas today announced it has commenced sample shipments of its new generation chipset, the SH-Mobile G3. Read on for more details.

So Multiple Cores - what does that actually mean? 

Current mobile phones use single core processors.  The processor / core is the brain of a computer (mobile phone) that performs the computational operations that make it work. Processors have tasks to perform (these are referred to as threads). A single core processor can only actively work on one thread at a time - effectively it performs it tasks sequentially. By contrast a multiple core processor is able to have several tasks at once (one for each core) - effectively this means it is able to perform tasks concurrently. Multiple cores are still one processor (they are physically made up of a single integrated circuit and may share memory), but in effect it is a bit like having multiple processors working in concert.

However in the mobile context it is actually the implications for power management (battery life) that are more significant. An OS can be written to allow cores to be accessed on demand (rather than having to power the whole processor). This means that functions that require less processor power are less battery intensive. For example most of the time a phone would run with just one core powered up, however when using processor intensive functions (e.g. capturing video) then the other cores would be powered up.

As phones get more powerful and use faster processors the lack of matching development in battery technology means that power management issues are only going to become more important.

The Symbian OS is already the most technically advanced of the major mobile software platforms in this area and Symbian believe it to be one of their key strengths. Support for ARM SMP architecture continues to build on this. 

Here's the more technical explanation as described in the Symbian press release: 

Symbian Limited today announced Symbian OS support for the ARM Symmetric Multi-processor (SMP) architecture. SMP support in future versions of Symbian OS will use multiple CPU cores to provide ‘performance on demand’ – battery life will be improved by accessing cores only when running demanding high-end multimedia applications and powering them down when they are not in use. This announcement is a milestone in Symbian’s strategy for power efficiency for converged mobile devices, reinforcing Symbian’s position as technology leader.

Symbian and ARM are long standing partners and have successfully collaborated on technology development and product planning for over 10 years. The ARM® Cortex™-A9 MPCore™ multicore processor was announced earlier today at the ARM Developers’ Conference. Symbian and ARM are working together closely on supporting Cortex-A9 MPCore multicore processor-based CPUs in Symbian OS.

Multi-processing technology underlies next generation Cortex-A9 processor designs. In converged mobile devices, SMP CPUs consist of multiple cores which can be individually powered up and down by the operating system. This delivers high performance for high-end applications such as games, browser-based intelligent services, and media-rich applications such as video streaming or TV recording, while offering low power consumption when the device is idle or executing less performance-critical tasks. Symbian believes SMP support is a crucial step in continuing to deliver industry-leading battery life in a world where converged mobile devices offer increasingly performance-demanding features with constant battery capacity.

In order to take full advantage of SMP, Symbian is taking the following technology steps:
• multi-processor support in the Symbian OS kernel and device driver model
• targeted enhancements throughout Symbian OS
• extended Symbian OS developer tools to allow developers to access the benefits of SMP
• Symbian OS validation on Cortex-A9 based hardware and models

Symbian has already started to deliver SMP technologies to its customers and will roll out the above incremental developments in future versions of Symbian OS. Details of this will be announced in due course. The first Cortex-A9 MPCore processor-based Symbian smartphones are expected in 2010.

SH-Mobile G3 

Renesas' SH-Mobile G3 chipset will be used in Symbian OS phones in Japan (FOMA-S), although it could also be used in other phones. The chip is the central part of the 3rd generation platform that is being developed jointly by NTT DoCoMo, Renesas, Fujitsu, Mitsubishi, Sharp, and Sony Ericsson. The first two generation of this platform have been used to create the majority of the existing Symbian phones in Japan.

The new chip enables data transfers by mobile phone at up to 7.2 megabits per second and also allows dual-mode communications, supporting both W-CDMA and GSM/GPRS standards. It is a single chip solution (used for both the telephony radios and application processing).  The new chipset will shorten development time and lower costs and will be used in phones available in second half of 2008.