Not long ago (5 years only), desktop computing encountered the same problem where mobile computing is headed today i.e. high power consumption for increase in processing power.
Problem was tackled with the introduction of multi-core processing allowing optimum performance with lower power consumption.
Similarly, the concept of mobile computing has reached to a whole new level with all new demands – with the introduction of mobile devices with processing power up to 1GHz. The trend is gradually shifting towards having desktop like web-browsing and video recording/playback experience on mobile gadgets. After all, if your device is capable of encoding/decoding 720p HD videos and can output it over HDMI then you’d probably prefer your pocket-sized portable device over a dedicated player more often.
After the release of Apple iPad and Samsung Galaxy Tab last year, mobile industry is speculated to see a lot of new tablets from different manufacturers this year. The expectations would be high in terms of performance and manufacturers will have to live up to them if they want to be in the contention.
Of course, they’d need capable hardware components to accomplish the tasks and offer support to different application developers.
What’s the Need of Dual Core Processing?
If an OS (Android, iOS or WinMo) running on top of 1GHz processor with dedicated hardware accelerated graphics chips, providing snappier UI performance than ever before and almost delivering desktop like web-experience on mobile devices then why is it all of a sudden that much necessary to switch to multi-core processing? Why not just enhance the processing power to let’s say 1.5 or 2 GHz to cater for the high end demands?
Think about browsing a website (over WiFi) containing ActiveX/JavaScript menus and having Adobe Flash contents, sending text messages to a list of recipients and social network application clients running in background, also having several OS specific processes running in parallel.
Single core processors can handle this level of multi-tasking but it’d be too much of a task. Since ActiveX/JavaScript codes require separate processing, Flash content also needs to be processed independently and there can be more than one instances of Flash objects, additionally, SNS applications clients are running with other processes in parallel so it’s obvious that under these heavy circumstances single core processor will be operating at its maximum frequency.
Higher the operating frequency of a semiconductor device, higher will be the power consumption (which actually defines the battery backup of mobile devices in our example).
Now, let’s think of having same processes but on a dual-core processing device. OS can easily distribute the jobs among the cores and both processors will be operating at normal frequency (no over-loading or operating at maximum frequency), thus, there’ll be no high power consumption.
This is, certainly, not the only case where dual-core processors will be required. There’re numerous examples where a multi-core processor is the next-best-thing to have e.g. 1080p HD video encoding/decoding, multi-threaded web browsers and applications, online gaming, support for stereoscopic cameras for 3D video capturing and 3D (glasses-free) video playback etc.
General Architecture, Manufacturers & Benefits of Dual-Core Processors:
Unlike desktop processors, mobile processors are based on System-on-a-chip (SoC) concept. An SoC, typically, has a processor, a dedicated graphics processing Unit (GPU), memory blocks, support for external connectivity interfaces and voltage & power management circuits.
A multi-core SoC consists of more than one processor cores or Digital Signal processor (DSP) cores, GPU, L1 & L2 cache blocks and also supports different features offered by the manufacturer.
Currently, three manufacturers are offering Dual-Core SoC based on ARMv7 Instruction set processor architecture.
nVIDIA’s Tegra-2, Qualcomm’s Snapdragon (3rd generation chipsets) and Texas Instruments’ (TI) OMAP-4 platforms offer dual-core processors with dedicated GPUs and manufacturer specific implementations of low power consumption algorithms. Both Tegra-2 and OMAP-4 based chips have ARM Coretx-A9 processor cores while the cores in Snapdragon platform chips have been designed by Qualcomm based on ARM architecture.
One of the major advantages of multi-core processing is the implementation of Symmetrical Multiprocessing (SMP) technology. SMP is being extensively used in desktop computing and ARM has introduced this concept to handheld devices with the introduction of Cortex-A9 Multi-processors. SMP architecture consist of two or more identical processor cores on a single chip with all cores sharing a common memory and controlled by a single operating system. All cores can work independently or in load-sharing mode whenever required.
In example, discussed above, OS is exploiting SMP to distribute the tasks among two cores keeping the device within power limits. Multi-threaded application and games can be benefited greatly by multi-core processors having SMP support since OS can assign multiple threads of an application to one or multiple cores depending upon the workload and type of activity thus optimizing performance. If required OS can even turn off other cores and utilize only one core for a specific operation. SMP can also enhance device UI experience for faster response since multiple applications running in background, at times, on a single core processor system result in delayed response to input commands.
Devices With Dual-Core Processors:
LG Electronics has taken the initiative to introduce world’s first dual-core mobile phone in the form of LG Optimus 2X, which is powered by nVIDIA Tegra-2 platform.
Motorola ATRIX is the other device sporting same dual-core hardware processing capabilities. Samsung have announced that successor of their coveted and highly successful device (Samsung I9000 Galaxy S) will also feature a dual-core processor.
It’s just the beginning of new generation of mobile phone; called SuperPhones by nVIDIA. A lot of new devices; including but not limited to mobile phones, featuring dual-core processors are expected to be announced at Mobile World Congress 2011 (Barcelona from 14-17 Feb 2011).
Final Words:
SMP supported Dual-core processor devices provide unparalleled opportunities to manufacturers and application developers.
They’re aimed at providing optimum performance and unprecedented user experience with support for cutting-edge technologies. Application developers have now lot of room available to effectively utilize the hardware capabilities of devices as multi-threaded support will greatly benefit their applications and games. While, current release of mobile OSes (Android for example) may not be optimized for multi-core devices but device performance can expected to be better when compared to single-core alternatives available.
Note: For further details on architecture and performance enhancements by multi-core processors, please refer to these whitepapers by nVIDIA and TI.
