Why multi-core processors are the future of tablets


The 2011 iteration of Mobile World Congress (MWC) has just ended and, as expected, the lines between smartphones and tablets have become more blurred as computer makers unveiled tablets with mobile wireless capabilities, and phone makers showcased new, powerful smartphones with even larger displays.

One thing that caught my attention though, is Nvidia's demo of a development tablet running on its new quad-core Tegra mobile processor. Code-named Project Kal-El, it was shown decoding a high resolution video stream of 2560 by 1440 pixels in real time without a stutter. And yes, this is a low-voltage processor specifically designed to power tablets and smartphones that we're talking about here.

While it isn't too difficult to grasp what a dual, or quad-core chip is from a technical perspective, users who have lived through the hot-headed era when multi-processor systems were the absolute rage might be left wondering what the big fuss was about. After all, we are crystal clear--and yes, I've assembled my own dual-processor rig once upon a time--that doubling the processor count doesn't equate to twice the processing capabilities, much less yield twice the speed.

I went in search of an answer, and it seems that chip designer ARM sat down recently with The Inquirer to elaborate on the advantages of multi-core processors. To put it in one word, it is all about power. Specifically, about how companies like Qualcomm can design a chip by mixing and matching processor cores of varying capabilities in order to meet a specific power rating. As I'm always fond of saying: Nobody wants a tablet that can only last for 2.5 hours on a single charge.

Bob Morris, director of mobile computing at ARM highlighted how running multiple cores at lower voltages can result in significantly lower power consumption. The reason is due to how a chip draws the most power when it hits peak processor utilization; an event that a processor with more than one core is less prone to. A live demonstration showing how a dual-core processor beat a single core variant in a benchmark was conducted to further illustrate the performance superiority of the former.

Of course, the bottom-line is that software must be first be optimized in order to take proper advantage of multiple cores.  The intriguing point here, though, is how multi-core processors can be made up of not just processing cores, but cores with specialized capabilities such as GPUs, or designed to speed up video decoding or encoding. Moreover, disparate processing cores can also be utilized, with the idea of a Cortex A9 and Cortex A5 working on the same silicon mooted.

Of course, with a deluge of tablets sporting dual or quad-core processors expected soon, it might make sense to put off any plans to buy a tablet until the latter part of this year. For now, I'm curious as to how many readers own a tablet--I would love to hear more about what you use it for. - Paul Mah  (Twitter @paulmah)