iPad 2 dual core, which apps use it?

[maflynn]

Again, that's not fully correct. Apps need to use GDC specifically if their processing rely on parallel processing. There is no free multi-core processing unless you submit your code block to the queue. This is in the API documentation

Agreed. Without apps being setup with GCD, there's little the OS can do to direct threads to both cores.

 

[LinkMx]

The key question really is how many app developers have threaded their apps, either using explicit thread APIs or by splitting off tasks for submission to GCD, and how many have written their apps as a single thread? I just did some searches on the developer forum here, hoping to see it alight with discussion on how to adapt to the dual core world, but there was very little there; I'm not sure what that means.

Even a single threaded app will almost certainly run faster on the iPad 2. Firstly I assume there will be the possibility for the app to have one of the cores all to itself with any background system processes and task completion of other apps being scheduled onto the other core, but I suspect more significant is the fact that with the A5 almost certainly being a Cortex-A9 design, that has about a 25% performance boost over a Cortex-A8 at the same clock speed.

- Julian

You could argue that an App that doesn't currently use threads wouldn't benefit much from multicore anyway, but like you said all apps will benefit from a faster processor even if they use only the main thread.

The other thing to consider is that Cocoa probably uses threading internally so even if the developer doesn't explicitly uses threads, there are parts of the app that'll take advantage of the two cores.

 

[Mike Reed]

When defending the restrictions placed on developers with language and library use, Steve Jobs mentioned that by forcing use of only their public APIs it enables them to control the progression of the platform. I think that will benefit the transition here for many apps.

For those implementing their own graphics systems writing against the low level rendering APIs the boost is likely only going to come from the speed and ram bump until they tweak their code. For everything else, they'll get that as well as at least some boost from Apple changing their own code to leverage the multiple-core processor.

One thing to consider is whether Apple intends the iPad 2 to obsolete the iPad 1. If app developers start writing code that assumes and performs well with multi-core iOS devices but only so-so on legacy devices then that presents an issue with app store fragmentation for iPad apps as well as universal apps meant to run on both iPads and iPhone/iPod touches. Though there is prescient for this, it is generally the exception and not the rule. While it is true that developers could write conditional code that behaves differently depending on it's host, from experience I can say that those aspirations have a habit of being forgotten in lieu of simply getting it done.