Originally Posted by
Mad Cabbie So, iOS is less hungry? Sure I read somewhere on here (could be wrong, usually am), that the Apple chip architecture was pretty much specific to the way in which iOS was set up, and by Apple overseeing the entire process from the chip to the hardware to ensure optimisation gave favourable results. I guess that's what you we're basically saying anyway? I've had a couple of iMac G5's in the past for DJing, and they always offered the most reliable and stable performance. As you state, it's probably the way the OS, or iOS is coded for optimisation.
Thanks Ascent! Long time no converse. ;-)
Well, the chip design is somewhat specific to iOS, but that probably doesn't mean what most people think it does. At it's most basic level it's still a standard ARM chip which is the same ISA everyone else in mobile is using. There is nothing specific about that.
At a higher level Apple has the freedom to combine SoC subsystems in ways that are best suited to their devices, e.g. if Apple designs a new phone where the pixel count of the display is doubled, then they can incorporate a GPU that completes raster operations exactly twice as fast while keeping the CPU as it is. This results in a user experience that is very consistent across devices (in terms of performance) despite the specs differing. It also makes it much easier for developers as they can ignore the performance impact that higher resolution displays otherwise have. In that way their SoCs are designed specifically for their devices, but none of that has anything to do with CPU efficiency. Apple does great work on that front too, but it's not any better than the great work Qualcomm does either. It's very much comparable.
What I'm referring to has almost nothing to do with software optimization however. It's about how the OSes are designed and what their developers decided was particularly important. Android and WP/WM both have run-time environments that sit between the hardware and the app. These environments provide runtime services for apps, like memory allocation and garbage collection, security monitoring, memory defragmentation, run-time type information and a whole host of other stuff. This makes it easier to program for Android and WP/WM and makes those developers more productive, but those services come at performance cost. iOS apps don't have that sort of run-time environment, so those apps run far more efficiently, but developers are required to do more work. Those run-time environments are also what allow Android and WP/WM apps to run on both Intel and ARM chips, whereas iOS apps are limited exclusively to ARM. That flexibility is nice, but it too comes at a performance cost. None of that has anything to do with optimization, but with different design priorities and goals.
