What can dual-core do for you: a course refresher what the A5 chip will bring to the Apple iPhone 4S

“Ask not for a dual-core gadget, ask what dual-core can do for you” is the way we would rephrase Kennedy's famous saying. Should we feel left in the dust next time someone flaunts their extra CPU core in our face, like in the case of the iPhone 4S, or can we live a long happy life with a single-core gadget, like the iPhone 4? We'll try to answer that question now that the first dual-core smartphones and tablets are lined up on the retail shelves, next to The Flash superhero comics.

We won't bother you with the technical details behind dual-core chipsets, we've written a separate article on that, if you want to know more. We'd rather point out that in this very moment you can get as much slick user interface and apps, high-definition video recording, and fast browsing from a WP7 handset, for example, with its two-year old single core 65nm processor, as from the first dual-core phones, whose chipsets are produced with the 45nm ARM Cortex-A9 design.

The typical user wouldn’t even notice that their brand new WP7 phone is sporting 2009 tech, since the platform is optimized for this exact CPU, and because of that, it runs faster and smoother than even some Android overlays powered by two Cortex-A9 cores. Not to mention how oily iOS and adjacent apps move on the iPhone 4, for instance, whose silicon is circa 2010.

To quote James Bruce, the lead mobile strategist of ARM: "Badly designed software will overcome quality hardware", and we couldn’t agree more. Only when the mobile operating systems and their applications are designed for multiple cores are we to see tangible benefits in the UI and app performance. So why are these guys waving their chipsets at us?

For now, the two visible advantages of having a dual-core CPU in your phone or tablet – Full HD 1080p video recording, and faster webpage rendering - are not on the top of everyone's list when choosing a phone, but they do hint at the possibilities that multicore chipsets are enabling.

Being able to shoot detailed video in 1080p does seem like the next step in the cell phone imaging evolution, however, especially when looking at handsets like the Samsung Galaxy S II and HTC Sensation 4G, which are capable of recording smooth 30fps 1080p video. Not to mention the 3D stereoscopic capturing that dual-core makes possible on handsets like the LG Optimus 3D, or the HTC EVO 3D.

Another area where dual-core shines is browsing. NVIDIA explains the page loading and script rendering speed phenomenon with dual-core very well in its Tegra 2 white papers. While most applications are written for single core processors, Android’s current WebKit-based browser is coded to take advantage of more cores, if available. With one CPU only, it is “slicing” its productive cycles – fetches the page, for example, then hits something like a Flash animation, processes the animation, then goes back to rendering the text, pictures and the rest of the website, until it hits the next thing, like JavaScript, which slows loading times.

Dual-core phones keep rendering the page with one core, while the other is executing a script, speeding pageloading and overall performance times significantly. ARM-based chipsets are also capable of what Intel calls HUGI (Hurry Up and Get Idle), boosting the cores when something needs to be executed quickly, then efficiently throttling down speed to preserve power.

Moreover, we can rest the case with Adobe Flash and performance with the dual-core chipsets – if decently coded, one can browse most heavily Flash-ed pages without a hiccup, making Apple all the more stubborn not to include support for it in its mobile browser. We can turn it off in Android, but with any dual-core phone you never need to. All in all, the browsing experience itself is worth getting a dual-core phone.

And now we come to the Achilles heel of dual-core phones and tablets – software support. The multicore optimization of Android Honeycomb will come to phones with Android Ice Cream Sandwich later this year, and Apple will have measures for taking true advantage of the A5 chipset in iOS. Apps, however, that are written from the ground-up for dual-core mobile chipsets, are few and far between - you probably have enough fingers on you to count them all both for Android, and iOS. As you can guess, they are mostly games, where CPU/GPU power matters most.

Great Battles Medieval has become the poster child when it comes to demoing how two or more cores are better than one on Android. As a real-time strategy game, it allows for hundreds of beautifully-rendered warriors to enter battle at once on your screen, complexity that would be impossible on single-core chipsets.

Apple’s iPad 2 has more apps optimized for the A5 chip to show for it. The iPad 2-optimized versions of Dead Space HD and Infinity Blade, as well as racers like Asphalt 6: Adrenaline HD, are boasting visual and gameplay enhancements that are only working with the new chip in the iPad 2. We also have A5-requiring versions of apps like iMovie, for example, which have been optimized to distribute the load between the cores, allowing for faster multitrack audio editing, and stitching videos without a hiccup. The deep voice-recognition integration called Siri in the new iPhone 4S also wouldn't be possible without the computational prowess of the dual-core A5: