AnandTech put up their iPhone 5S review today but I’m not interested in the phone itself per se. I’m interested in the new phone’s SoC more than anything else (the new fingerprint scanner is a distant second).
AnandTech’s analysis was fascinating. If you’ve got the time, I suggest you read the analysis in its entirety. If you don’t have time, here are some of the highlights which I thought were noteworthy.
- 64-bit dual core CPU
- 1.3 GHz clockspeed
- 1GB LPDDR3
The move to 64-bit may appear premature but AnandTech has a good theory:
The more I think about it, the more the timing actually makes a lot of sense. The latest Xcode beta and LLVM compiler are both ARMv8 aware. Presumably all apps built starting with the official iOS 7 release and going forward could be built 64-bit aware. By the time 2015/2016 rolls around and Apple starts bumping into 32-bit addressability concerns, not only will it have navigated the OS transition but a huge number of apps will already be built for 64-bit. Apple tends to do well with these sorts of transitions, so starting early like this isn’t unusual. The rest of the ARM ecosystem is expected to begin moving to ARMv8 next year.
Even though Apple isn’t utilizing the additional address space at the moment, the move to 64-bit does bring a smidgen of benefit elsewhere:
As A64 is a brand new ISA, there are other benefits that come along with the move. Similar to the x86-64 transition, the move to A64 comes with an increase in the number of general purpose registers. ARMv7 had 15 general purpose registers (and 1 register for the program counter), while ARMv8/A64 now has 31 that are each 64-bits wide. All 31 registers are accessible at all times. Increasing the number of architectural registers decreases register pressure and can directly impact performance. The doubling of the register space with x86-64 was responsible for up to a 10% increase in performance.
Apple took steps towards the inevitable 64-bit future by converting every one of their own applications in iOS 7.
As always, Apple takes its GPU performance seriously. The GPU included in the A7 is the latest and greatest from Imagine Technology. The doubling of performance wasn’t evident across all the benchmarks but it did manifest itself in game scenarios. And because of its inclusion, the iPhone 5S may remain relevant for longer than before.
I cannot wait to see this A7 in the next iPad.