2012 is shaping up to be the year in which quad-core CPUs are finding their way into the leading smartphones and tablets, but whilst more cores certainly does give some benefits is more always better? nVidia are pushing their Tegra 3 CPU which offers quad-core performance plus an extra fifth-core that only sips power to increase battery life, but Qualcomm is claiming their dual-core S4 Snapdragon chips outperform nVidias offerings, and texas Instruments is claiming much the same from their OMAP5 chips. So how do you know which is best for you?
The first thing to get out of the way is the belief held by most consumers that a higher clock-speed means better performance. Whilst this may have been true a few years ago, and was certainly something Intel pushed in their marketing for Pentium processors, this simply does not hold true today. The architecture of the chip can mean that performance of an 800MHz CPU can outperform a 1.2GHz CPU using a different one as was demonstrated by Texas Instruments when showing off their latest OMAP5 chips. In this case, the dual-core OMAP5 chips, which make use of ARM Cortex A15 architecture, were compared on rendering benchmark performance against a quad-core chip that used the older ARM Cortex A9 architecture, such as used in nVidia’s Tegra 3, and beat it by quite some margin even with a 1/3rd lower clock-speed. The A15 architecture does use more power than the A9 at the same clock-speed, but with much better performance and efficiency even at lower speeds – but TI are looking to offer these at 2GHz too, so that is a lot of oomph.
So why the move to quad-core? Well there are some applications that make use of the multiple core such as video encoding and decoding and some games – and with these tasks, being able to spread the load over multiple cores can be very useful. But the majority of tasks still only make use of a single core – as you can tell from Microsoft’s own Windows Phone 7 only supporting single cores until quite recently. The Tegra 3 takes an innovative approach to offering multiple cores with its low power fifth-core, that is used for many of the basic phone tasks and using very little power, before automatically starting the four main cores if needed for something processor-heavy. It is just a shame that the four cores it does offer are a generation behind the Cortex A15 cores found in the latest batch of dual-core processors from their competitors.
What we are seeing now is some serious competition in the CPU stakes, with different manufacturers taking ARM’s architectures and adding their own special tricks to make them stand-out from the crowd. Qualcomm, for example is changing the balance between the main CPU cores, with its integrated Adreno GPU and ability to run each core asynchronously meaning it too has power saving abilities. TI is offering partnerships with other companies such as Harmon and iRobot to integrate other technologies onto its Cortex A15-based chips, making for less space needed by device manufacturers for other chips and allowing for smaller boards and therefore smaller smartphone form-factors. There is a lot of variation under ARM banner.
So the question remains – which chip to look out for? Well, whilst each of these platforms can demonstrate performance improvements in certain areas due to design and added extras, consumers are really left to the whims of smartphone and tablet manufacturers and which platforms they prefer. But whichever of the latest platforms you end up with, you can rest assured they are leaps and bounds ahead of those available just 18 months ago, and they will be bettered just as quickly. Progress in the mobile space has never been faster.