Octa-core processors: Real advantage or marketing myth?

Just as processor clock speeds were once considered the sole measure of a PC's performance in the 90s, core count is becoming today's default indicator of smartphone power. While dual-core devices were all the rage just a short while ago, customers are now demanding quad-core at the very least, and manufacturers are racing to one-up the competition by pushing out phones which have octa-core processors in them.

Enabling this phenomenon is MediaTek, a manufacturer of ARM-based processors which, until the recent spate of low-budget Android devices, had managed to maintain a pretty low profile. MediaTek's processors are based on the industry-standard ARM architecture, but are generally not as powerful or as integrated as those from more well-known competitors such as Qualcomm.

MediaTek offers a variety of models, most of them aimed at the lower end of the smartphone market. However, they've been quick to sense the growing interest in boasting about core count, and have developed an octa-core chip, the MT6592. So far, three phones have launched in India with this processor: the Intex Aqua Octa, the Wickedleak Wammy Passion X, and the Micromax Canvas Knight. Karbonn has also recently announced the Titanium Octane and Titanium Octane Plus models, which will join this exclusive club.

Is eight better than four?
Various ARM licensees have been offering eight-core configurations for a while now, but their approach is to have one cluster of four high-powered cores which don't prioritise energy efficiency, and another of four low-powered cores which are much easier on the battery. Depending on the amount of work the processor is called upon to do at any point, it can rapidly switch between the two clusters.

ARM calls this arrangement big.LITTLE, and claims that it can be used to achieve far better control over power efficiency than is possible with clock speed scaling alone. The high-powered and low-powered cores do not generally operate at the same time, although this is possible in certain implementations and is known as heterogenous multiprocessing.

MediaTek, on the other hand, is proud to boast that its MT6592 is a "true octa-core" chip, in which eight cores of the same design can operate simultaneously. While eight simultaneous cores would obviously be able to deliver superior performance to four, Mediatek's building blocks themselves aren't the most powerful. The architecture is also heavily dependent on the way the OS and applications are written.

Ideally, having more processor cores should allow a device to be more responsive, which means multitasking should feel snappier. Applications shouldn't have to wait as long for the processor to allocate resources to them, and cores not in use should be able to shut down completely in order to minimise their impact on battery life.

conclusion

Ultimately, we can see that "octa-core" isn't just a marketing term. There are clear advantages to having the spare processing power, and MediaTek seems to have found a way to implement an eight-core SoC within a budget, and without killing battery life. While Qualcomm might not have had much to worry about before, it also seems as though eight weaker cores can hold their own against four stronger ones; a fact which is already leading to some interesting market dynamics in the sub-Rs. 20,000 price range.

So what's next? Will MediaTek refine its products and processes enough to take on the high-end Snapdragon 600 and flagship-class Snapdragon 800 series? Will Indian brands ride on MediaTek's coattails and start pushing into the premium space and create pricing headaches for multinational brands? Will Qualcomm lose its position as the best vendor for top-tier smartphone and tablet processors? We can't wait to find out.