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Why Apple Went 64-Bit With the iPhone 5s
Hugh Pickens DOT Com writes "Adrian Kingsley-Hughes says it's not just because Apple likes bragging about being first and because a 64-bit processor sounds cooler than 32-bits that Apple used the 64-bit A7 chip in the new iPhone 5s. A shift from a 32-bit processor to a 64-bit part paves the way for iPhones to be fitted out with 4GB+ of RAM down the line, but more importantly the move brings iOS and OS X apps much closer. The architecture for 64-bit apps on iOS will be almost identical to the architecture for OS X apps, making it easy to create a common code base that runs in both operating systems. 'Apple has slowly been bringing iOS-like features to Mac OS for years now: think of Launchpad and Gatekeeper,' writes Sascha Segan. 'The ultimate prize, of course, would be to bring the million-plus iOS apps to Macs. Apple could do that with an ARM-compatible virtual machine on Mac hardware, but it would want the VM, the OS and the associated apps to play nicely in the much larger memory space available on Macs. That means moving the whole system over to 64 bit.' By unifying iOS and Mac OS with Xcode developer tools in a 64-bit space, Apple could once again leap ahead of Microsoft and Google, says Segan. Microsoft hasn't yet been able to leverage its desktop strengths to achieve success as a mobile OS. The 64-bit chips for Android devices aren't ready, and neither is Android itself."
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Several journalists have made this mistake, such as the drivel posted here: Trusted Reviews
They seem to think that the register size being equal means that software written for them is somehow much more similar. In reality the CPUs and the software they run are no closer to each other than before. The main benefit of this move to the latest ARM CPU design is ironically much the same as the advantage brought by x86_64 - more registers are now available and some floating point operations are more efficient. This will translate into a small performance increase but it won't be night and day.
Apple's move to the 64-bit ARM platform isn't about compatibility with OSX, support for over 4G of ram (per process, the 32-bit ARM processor can handle 1TB of RAM already) or for performance reasons (the additional memory load will almost undoubtedly overpower the slight increases in the 64-bit ARM processing improvements).
If you read through ARM's announcement of it's 64-bit platform a large portion of it is dedicated to the new security layer allowing for better segmentation between applications and a more in-depth security layer in between the segments. This will allow Apple to sit a hypervisor below the kernel and protect the system from "attacks" and if we can get through the hypervisor there is an additional ARM security layer before you can run in the top processor privilege layer.
64-bit ARM isn't about anything other than preventing jailbreaking.
You're not important enough to add to this list.
http://www.macobserver.com/tmo/death_knell
It's more like they didn't have much else for the iPhone 5S, just the fingerprint sensor. Everything else is either the same or a slight improvement, like the camera.
const int one = 65536; (Silvermoon, Texture.cs)
SJW, n: "Someone I don't like, and by the way I'm a fuckwit" - AC
Your washing machine doesn't even need a 32-bit processor.
You would be surprised The question is, do you want to put up with 8051 weirdo nastiness or a nice clean arm design. The original 8051 was about 30K transistors, so was the ARM 2. Which would you rather program?
Since those days, transistor density increased more than a factor of a thousand, essentially wiping out the cost advantage of 8 and 16 bit processors, they all cost less than a buck. And see this coherent argument for why a 32 bit arm may be more efficient than an 8 bit 8051 variant: it takes way fewer cycles to get things done.
Finally, there is productivity. Quick to market counts for a lot, and low engineering costs means shorter, more agressive product cycles. The modern manufacturer just can't afford to have expensive engineers futzing around with processor limitations.
I don't know about you, but my new LG washing machine seems to put a lot of thought into what it's doing in order to get the clothes clean using the least amount of power and water, with dozens of different options. They probably saved some parts cost by implementing the motor controller in software. I would not be surprised at all to learn that they spent a buck to put a 32 bit arm core in it. My next washing machine will be on my home network and when it's done it will notify my cell phone. Probably running Linux.
When all you have is a hammer, every problem starts to look like a thumb.