Apple Devices iPhone 5S, A7, apple, iphone 5s, processors — September 18, 2013 12:24 — 0 Comments
iPhone 5S: are the A7 chip’s 64 bits useful, or are Apple simply showing off?
From the Guardian: Engineers who have worked with ARM technology since the 1990s explain whether Apple’s A7 CPU is for show – or for work
When Apple announced that its iPhone 5S would has a 64-bit processor, the reaction from the tech community varied from “Huh?” to “Wow!” to “There’s no point in that now.” So does it have any benefit, now or in the future?
To understand this, we have to go back to basics, and work back up to the overall view, say Andrew Hodgkinson, Steve Revill and Ben Aviso, founder members of RISC OS Open Ltd.
Most computing devices work with binary values grouped together to represent larger numbers. The bigger the grouping, the greater the range of numbers the device can easily represent. A device’s CPU is usually described as “64-bit” if, broadly, it uses 64 binary digits as its fundamentally most efficient unit of representation.
The idea of 64-bit computing isn’t new. Even in the early 1960s, IBM built a supercomputer with 64-bit and 32-bit capabilities. Reductions in size, affordability and energy consumption have brought such technology into the mainstream. Today, most new desktops and laptops use 64-bit CPUs. Smartphones and tablets still used 32-bit processors until Apple announced the iPhone 5S – with a 64-bit ARM-based CPU.
A conventional 32-bit CPU in a modern smartphone can still do 64-bit mathematical operations, but because to do so it needs to join two 32-bit numbers together (to represent a single 64-bit number), it often takes longer to do than a native 64-bit CPU.
For an idea of the vast range of numbers a 64-bit CPU can represent, imagine that a single bit had the physical volume of a grain of rice – 0.075ml according to Wolfram Alpha. 16-bits-worth (65,536) of grains, crushed to eliminate gaps, would fill around 10.5 pint glasses. 32-bits worth of rice would occupy the same space as three London buses. But 64-bits worth of rice would fill the whole of Sydney Harbour… 2,460 times over.
Who could possibly need all that in a phone?
Read the full article here: