The iPhone 5's A6 SoC: Not A15 or A9, a Custom Apple Core Instead
by Anand Lal Shimpi on September 15, 2012 2:15 PM EST- Posted in
- Smartphones
- Apple
- Mobile
- SoCs
- iPhone 5
The A6 GPU: PowerVR SGX 543MP3?
Apple made a similar "up to 2x" claim for GPU performance. It didn't share any benchmarks, but there are four options here:
1) PowerVR SGX 543MP2 (same as in A5) at 2x the clock speed
2) PowerVR SGX 543MP4 at the same clock as the MP2 in the A5
3) Marginally higher clocked PowerVR SGX 543MP3
4) Next-gen PowerVR Rogue GPU
It's too early for #4. The first option makes sense but you run into the same issues as on the CPU side with higher voltages used to ramp clocks up (also possible that you drop voltages in the move to the new process technology).
The second option trades voltage for die area, which based on the A5X Apple is clearly willing to spend where necessary.
The third is sort of the best of both worlds. You don't take a huge die area penalty and at the same time don't run at a significantly higher frequency, and you can get to that same 2x value.
The third option is the most elegant and likely what Apple chose here. Remember that overall die size is dictated by the amount of IO you have around the chip. The A5X had four 32-bit LPDDR2 memory controllers, which gave Apple a huge die area to work with. The move to a smaller manufacturing process cuts down the total die area, which means Apple would either have to add a ton of compute (to fill empty space, no sense in shipping a big chip with a bunch of unused area) or reduce the memory interface to compensate. Pair that knowledge with the fact that Apple doesn't have the same memory bandwidth requirements on the iPhone 5 (0.7MP vs. 3.1MP display) and it makes sense that Apple would go for a narrower memory interface with the A6 compared to the A5X.
How much narrower? Phil Schiller mentioned the A6 was 22% smaller than the A5. We can assume this is compared to the 45nm A5 and not the 32nm A5r2, which would mean that we don't have any more memory channels compared to the A5. In other words, it's quite likely the A6 has a 2x32-bit LPDDR2 memory interface once again.
Final Words
There's not much more to add for now. We'll have a device in a week and I suspect the first reviews will be out a day or two before then. Then the real work begins on finding out exactly what Apple has done inside the A6. If anyone has been dying to put together some good low level iOS benchmarks, now is the time to start.
This is a huge deal for Apple. It puts the company in another league when it comes to vertical integration. The risks are higher (ARM's own designs are tested and proven across tons of different devices/platforms) but the payoff is potentially much greater. As Qualcomm discovered, it's far easier to differentiate (and dominate?) if you're shipping IP that's truly unique from what everyone else has.
Now we get to see just how good Apple's CPU team really is.
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secretmanofagent - Sunday, September 16, 2012 - link
Same here. I've enjoyed the Krait in-depth reviews as well. Keep up the good work.abishekmuw - Sunday, September 16, 2012 - link
It seems that all the performance gains shown off by Apple are storage bound (launching app, saving files, viewing files).. there doesn't seem to be a performance data point for CPU bound tasks (browsing, imovie, garage band, etc). doesn't this make it more likely that the iphone could be faster because of improved storage (or filesystem), and not just a faster CPU?jwcalla - Sunday, September 16, 2012 - link
Well that new Samsung NAND flash has like 4x the performance of previous flash (140 MB/s reads, 50 MB/s writes, plus good IOPS), but who knows if Apple decided to dip into that territory.The "up to 2x faster" claim is probably a combination of improvements in the CPU, memory, storage, and compiler.
Unfortunately, the benchmarks won't be able to isolate the CPU performance alone since there's no control / standard to compare it to. They'll show A6 vs. Krait vs. Exynos, etc., but one can't really draw much of a conclusion about the CPU itself. You're basically benching the "total package".
The LLVM / Clang compiler that Apple uses is actually very well-tuned for ARM architectures.
UpSpin - Sunday, September 16, 2012 - link
Exactly. If the A6 is really 2 times fater than A5, they easily could have added a synthetic benchmark result which shows that the A6 computes 2 times faster, just to satisfy tech sites. But they didn't, they focused on things which could be caused by software optimizations (accelerated through GPU) or other tweaks as you said (storage).I expected that the iPhone 5 will have a A15 to remain competive with next gen Android smartphones. Now I think the A6 is even less impressive than Anand believes it is. No A15, just a A9 with A15 like improvements, maybe worse than Qualcomm Krait. The biggest improvement: die shrink.
darkcrayon - Sunday, September 16, 2012 - link
They also said 2x graphics performance, and none of the examples had *anything* to do with GPU. It won't take long for us to find out at least.Shamesung-korean-made - Sunday, September 16, 2012 - link
LOL! I think talk of A15 had fandroid fans running scared! Galaxy s3 - designed by KOREANS!cacca - Sunday, September 16, 2012 - link
Strange that in this article you don't comment that all the previous iPhone compatible gadgets/hardware con be thrown out the window.So your alarm clock, hi-fi system, speakers, docking stations... everything is not compatible.
Obviously you can buy, for the usual high price, an adaptor (that will not be physically compatible with all your previous generation gadgets). Remember to buy the cable too.
So you end paying 100$ more (check the prices for adaptor and lighting cables), just to connect it to your PC/Apple.
Are all apple users so used to be swindled? Are mentally impaired? There was no real technical reason to change, exuding the usual one.... grab zealot money.
Welcome to Apple, a company dedicated to the studies of the of fanboysm and logic limits.
asendra - Sunday, September 16, 2012 - link
Are you for real?First, you don't need 100$ in order to connect it to your pc, it comes with the usb cable. I assume you pc does has usb right?
No technical reason? Besides the fact that it is 5 times smaller, symmetrical and all around a better connector more suited to modern technologies..
Besides, could you care to point ANY company that has kept the same connector for nearly 9 years? I think It was long overdue and people has had more than time to benefit from their purchases.
I could point to many OEM who see fit to change their charger/connector every 6 months, but hey, all of us know they aren't screwing anyone because no one buys accessories for those devices.
UpSpin - Sunday, September 16, 2012 - link
If they changed the connector, thus made every iPhone 4S and previous accessory incompatible, why have they introduced a new proprietary connector and haven't made use of the standard micro USB connector.True, the iPhone 5 connector, thanks to its symmetry, is more handy. But that's the only advantage, the disadvantage of introducing a new propiertary connector, if a standard connector is established already, is much larger. You still have to carry an USB micro adapter with you, you additionally have to carry an adapter for your old accessories which you won't upgrade in the near term (car dock, hifi station), so why not just move to USB and get compatible with all the USB standards? (MHL)
doobydoo - Sunday, September 16, 2012 - link
You don't need to carry any USB micro adapter with you, at all. What on earth are you on about.You don't need microUSB full stop. I've honestly never used it - not once, in any device.
You take the SUPPLIED cable and plug it into your pc, or use the SUPPLIED cable to charge your phone. How are you struggling with that?
Regarding lightning vs microUSB, unless you've extensively benchmarked both and know the absolute limitations and performance of both - you simply cannot make any claims regarding any benefits it may or may not have.