Digital Foundry vs. iPad 2

The beginning of this wave of updates has already begun. In yesterday's Digital Foundry article, we talked with Australian development studio Firemint on how Real Racing 2 HD added 1080p support amongst a whole host of other visual improvements that could only be accommodated on the A5 platform. Firemint worked to a series of speculative performance models on supporting iPad 2, then built on that work when the full spec was announced at Apple's iPad 2 keynote.

American developer Epic Games was rather more fortunate, involved in the keynote itself and demonstrating an enhanced version of Infinity Blade. They clearly had access to iPad 2 prototypes ahead of the launch, and boy, does it show in the recently released upgrade. The game had a decent enough performance level on the original iPad, but some users had pointed out that Infinity Blade ran smoother on the fourth-gen iPod Touch and iPhone 4 and even featured more visual effects, such as additional specular maps.

The new dual-core CPU and PowerVR graphics tech in iPad 2 more than redresses the balance, and then some. Not only is the patchy frame-rate issue resolved, but image quality is greatly increased, not least through the implementation of some seriously impressive anti-aliasing. This is a hardware-based implementation which we can also expect to see on Sony NGP and owing to the tile-based deferred rendering approach in PowerVR tech, the hit to performance is minimal.

"Anti-aliasing was one of the key focus areas for Series5XT and the impact on performance is as low as possible without sacrificing image quality," PowerVR maker Imagination Technologies told Digital Foundry in a recent GamesIndustry.biz interview.

"We fully expect that AA will be enabled for the majority of content going forward due its low impact as can be seen on GLBenchmark where the difference between AA on/off is just small performance fluctuations due to background tasks."

The transition across to the new hardware needn't cause developers too many headaches either.

"You will get a big performance boost for free without making any code changes. Beyond that it's a matter of tailoring your CPU code and graphics engine to take advantage of the additional horsepower," explains Firemint CEO Rob Murray.

"There is no need to use any new libraries to see how much faster everything runs on iPad 2. If you want to use the CPU to its fullest though, you may want to think about how you architect your code to utilise multiple threads and there are some more sophisticated things you can do with Apple APIs."

The move from a single-core CPU architecture to the dual-core iPad 2 can see additional performance gains through explicitly addressing the multi-core environment, with the tools to do so already incorporated into Apple's development environment.

"Utilising threads within your game will activate the multi-core CPU without having to do any magic. We have some threads within Real Racing 2 HD that have benefited from this," Murray adds. "However you can use some of the Apple SDK to take tight control over multi-core CPUs, so that is something exciting to explore in the future."

Epic's Infinity Blade has rightly been held up as the standard bearer in cutting edge mobile graphics, so as an example of how iPad 2 looks at its best right now, and as a taster for visual quality going forward, this performance analysis is as good as it gets. Bearing in mind that this is an existing iOS title with added bells and whistles, it's safe to say that titles designed with A5 specifically in mind could look a whole lot better going forward.

We were genuinely taken aback by the improvement in the quality of Infinity Blade's visuals on iPad 2, and the higher frame-rate helped to make the game feel more responsive and consistent. It truly is a tantalising example of just what is possible on the new architecture in the here and now, but for owners of the original iPad perhaps looking to upgrade, a really good question to ask is whether now is the right time to do so.

This is not the first generational leap in graphical potential we've seen on the iOS platform. With the launch of the iPhone 3GS and the third-gen iPod Touch, Apple upgraded its PowerVR tech to the SGX535 line, which includes the support for OpenGL ES 2.0 and the programmable pixel shaders that made the Unreal Engine 3 conversion possible. However, aside from the usual speed increase, it took a long time for any software to come along that genuinely made use of that additional power. Clearly, it made better business sense for iOS game-makers to keep on developing for the hardware already out there and it took a big studio with the resources of Epic Games to make the next big step.

In the here and now there is little doubt that the vast majority of games will run just as well on existing iOS devices as they will on iPad 2: most of which will not be using state-of-the-art tech like Unreal Engine 3. In the excitement of looking at new technology it's worth remembering that the lion's share of new iOS releases are actually 2D in nature. However, while adoption of the iPhone 3GS's SGX535 tech was a prolonged process, there are a number of factors suggesting that things will be very different this time. Apple obviously has very big plans for the games market.