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发帖数: 11103 | | p*******m
发帖数: 20761 | | p*******m
发帖数: 20761 | 3 Hardware support and a 64-bit timeline
First, a broad outline of the major milestones in the journey to 64-bit.
Just to recap: 64-bit support in mobile devices is less about the 4GB RAM
limit that drove the transition on the desktop and more about the
architectural enhancements and performance improvements included in the
ARMv8 instruction set. 64-bit iOS CPU benchmarks run around 30 percent
faster than 32-bit benchmarks running on the same hardware.
September 2013: Apple introduces the iPhone 5S. Its Apple A7 chip makes it
the first 64-bit iDevice. iOS 7 is the first 64-bit version of iOS, at least
when running on the A7.
October 2013: The iPad Air and what is now called the iPad Mini 2 are
introduced. Both include the Apple A7 SoC.
March 2014: iOS 7.1 is released. It resolves most of the memory-related
crashes in 64-bit iOS.
September 2014: The iPhone 6 and 6 Plus are released. Their Apple A8 chip is
Apple's second 64-bit SoC. Apple stops selling the iPhone 4S, making the
iPhone 5C the last of the 32-bit iPhones.
October 2014: The iPad Air 2 and iPad Mini 3 are released. Both include 64-
bit chips (the A8X and A7 again, respectively). The fourth-generation Retina
iPad, which had been on sale for $399, is discontinued. The original iPad
Mini is the last of the 32-bit iPads.
February 2015: All new apps submitted to the App Store must include 64-bit
support.
June 1, 2015: All app updates submitted to the App Store must include 64-bit
support.
June 19, 2015: Apple quietly discontinues the original iPad Mini. The only
32-bit iPads Apple now sells are refurbished.
The hardware transition is nearly complete, which is sort of astounding
given that the first 64-bit iDevice came out less than two years ago. In all
likelihood, the iPhone 5C will fall off the end of the lineup when new
iPhones arrive. The iPad is already there.
The two major holdouts are the iPod Touch and the Apple TV. Rumors about a
new version of the set-top box have been lingering for years, and it has to
happen sometime, but in any case it's clearly in the works.
As for the iPod Touch, well, those iTunes product shots don't give us a lot
to go on. Assuming the renders are accurate and not just some Photoshop
mistake (a common occurrence), they don't include the little camera loop
that the fifth-generation Touches have, suggesting the potential for other
internal changes. That's all we have to go on, aside from the fact that it
just makes sense to move the Touch away from the aging 32-bit A5 and its
512MB of RAM (iPods aren't big sellers anymore, but iPod Touches are useful
as development devices or as pocket computers for non-smartphone users). |
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