Apple's Swift: Visualized

Section by Anand Shimpi

Based on my findings on the previous pages, as well as some additional off-the-record data, this is what I believe Swift looks like at a high level:


Note that most of those blocks are just place holders as I don't know how they've changed from Cortex A9 to Swift, but the general design of the machine is likely what you see above. Swift moves from a 2-wide to a 3-wide machine at the front end. It remains a relatively small out-of-order core, but increases the number of execution ports from 3 in Cortex A9 to 5. Note the dedicated load/store port, which would help explain the tremendous gains in high bandwidth FP performance.

I asked Qualcomm for some additional details on Krait unfortunately they are being quite tight lipped about their architecture. Krait is somewhat similar to Swift in that it has a 3-wide front end, however it only has 4 ports to its 7 execution units. Qualcomm wouldn't give me specifics on what those 7 units were or how they were shared by those 4 ports. It's a shame that Intel will tell me just how big Haswell's integer and FP register files are 9 months before launch, but its competitors in the mobile SoC space are worried about sharing high level details of architectures that have been shipping for half a year.

Apple's Swift core is a wider machine than the Cortex A9, and seemingly on-par with Qualcomm's Krait. How does ARM's Cortex A15 compare? While the front end remans 3-wide, ARM claims a doubling of fetch bandwidth compared to Cortex A9. The A15 is also able to execute more types of instructions out of order, although admittedly we don't know Swift's capabilities in this regard. There's also a loop cache at the front end, something that both AMD and Intel have in their modern architectures (again, it's unclear whether or not Swift features something similar). ARM moves to three dedicated issue pools feeding 8 independent pipelines on the execution side. There are dedicated load and store pipelines, two integer ALU pipes, two FP/NEON pipes, one pipe for branches and one for all multiplies/divides. The Cortex A15 is simply a beast, and it should be more power hungry as a result. It remains to be seen how the first Cortex A15 based smartphone SoCs will compare to Swift/Krait in terms of power. ARM's big.LITTLE configuration was clearly designed to help mitigate the issues that the Cortex A15 architecture could pose from a power consumption standpoint. I suspect we haven't seen the end of NVIDIA's companion core either.

At a high level, it would appear that ARM's Cortex A15 is still a bigger machine than Swift. Swift instead feels like Apple's answer to Krait. The release cadence Apple is on right now almost guarantees that it will be a CPU generation behind in the first half of next year if everyone moves to Cortex A15 based designs.

Custom Code to Understand a Custom Core Apple's Swift: Pipeline Depth & Memory Latency
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  • darwinosx - Tuesday, October 16, 2012 - link

    The iPhone 5 display is better than any current Android display.
    But Motorola and Android if you want a company that is dying and being sold and a copycat cheap phone with no service and support.
  • V-Money - Tuesday, October 16, 2012 - link

    Your wisdom and informative argument adds tremendous value to this post. For the record though, the OP said specifically battery life and 720p display, so the response was relevant.

    The rest of your post is petty, get over yourself. If you are going to play the copycat card you should have done it before Apple decided to go with a bigger screen and use a (eerily similar) notification bar to what Android phones have had for years.

    As for quality (of display or otherwise), that is subjective analysis and considering that Apple only releases one phone at a time and Android manufacturers many, its a stupid argument for anyone to make. Case and point, I can find many android phones that are much more terrible than the iPhone, but I can also find many that are better. The iPhone is a decent phone, but its not for everyone. Every consumer has their preference.

    My point being there is not one-size-fits-all phone, so quit acting high and mighty with your close mindedness. You are not better than those around you because you bought into Apple's marketing, you are just a fool dealing with the first world problem of living such a meaningless existence that you have to hold on to the imaginary power an inanimate object pretends to give to you.
  • Alucard291 - Tuesday, October 16, 2012 - link

    I feel that your argument may be too good for him to reply to :)

    He seems awfully angry :D
  • crankerchick - Tuesday, October 16, 2012 - link

    Great reply. If there's one place I just want to exchange comments without playing the "my toy is better than yours" game, it's here on AnandTech.
  • Gradly - Wednesday, October 17, 2012 - link

    I'm sick of ppl comparing iPhone to other devices. I'm sick of those telling you iPhone borrowed the notifications slider form android and skipping the myriad of things that other borrowed form iPhone. Apple has always said that "we are not the first but we do it the best". I'm sick of those who still don't realize that before iPhone ppl were living in caves actually.

    I'm an Apple lover not an Apple fanboy. I just adore the design, aesthetics, and GUI of Apple devices.
  • Penti - Wednesday, October 17, 2012 - link

    It's sadly Apple that goes and patent UI-elements to use against their competitors that is why it's always brought up. It would be totally unnecessary otherwise. You might look at who's the inspiration otherwise and it's often not Apple. In reality we had capacitive touch screens (it's not Apples tech of course) before, app store before, Android even had an SDK out before Apple. Competitors like Symbian/Nokia, HP WebOS, and Blackberry are even allowed to use stuff like bounce back effect even without (or before) any agreement with Apple. They should have credit but they didn't all the sudden bring out their device with what we now call smartphone features, it lacked most functions at first and slowly iterated, it did a lot poorer in many areas then it's competitors was doing even before iPhone and the first few years it also showed in sales numbers which were not high at the first 2-3 years. It did show us how important a good platform was. Guys like Rubin had already figured that out though. So I'm not sure what they would borrow. Full WebKit-browsers on mobile is a good example of stuff they are co-developing but it was out in Nokia devices in 2006, netfront and Opera was never good alternatives to build into your platform. Stock Android don't have the bounce back effect, UI's looking like Apples and so on. Not even TouchWiz on Samsung's tablets looks like or infringes anything (design-wise) by Apple. They clearly have their own ideas. They are not the "me too", others might try to emulate them more in a business sense though. But they will be punished by the market by their execution instead of by Apple. It's not like any of the major players are fruit ninja-clones though.

    iPhone was desperately rudimentary at first. It didn't do applications and the web, messaging, photos etc better then anybody. What they did good was to iterate and improve. They take enterprise / corporate customers more seriously then Microsoft and so on in this field. Even if it took some time for them to get there. So they do plenty of good. It's a good platform, but it's not like they gave their competitors their blueprints for their devices / os of today back in 2007 and both have made many improvements. Well maybe not Microsoft but it takes a few years to start over. Apple has even got into hardware (components) a bit. Commoditization and convergence has reached far beyond the mobile field. That's great even if Apple won't enter them. Still don't know why any competitor would like to turn themselves into a retail giant and employ mostly store staff as Apple does – Microsoft should start doing what they are good at instead. Google would be the most evil company in the world if they had started to patent and sue based on UI-features and methods. Or if they really tried to stop Bing and Bing Maps (and getting it banned in some markets) for example. It doesn't really matter who was first and who invented what if you take it to court were that doesn't really count and that creates a lot of BS surrounding the whole issue and companies involved that is largely unnecessary. But the real silly thing is why they fight. It's not based on IPR, it's basically that they want to be alone in doing whatever, even if they can't really make that claim to have sole rights to something. But ultimately courts do get that under control even when corporate leaders turn to fighting outside of releasing product.
  • slickr - Tuesday, October 16, 2012 - link

    LOL. Don't make me laugh. It has still the worst display and has had the worst display for at least 3 years.
  • A5 - Tuesday, October 16, 2012 - link

    Your response is just as dumb as his. The iPhones have excellent displays.
  • medi01 - Wednesday, October 17, 2012 - link

    None of the iPhones have anything to compare with AMOLEDs, on top of having idiotic resolution.

    On tablet space, only iPad 3 matched color gamut of THE FIRST Samsung Galaxy Tab.
  • thunng8 - Wednesday, October 17, 2012 - link

    How does 67.5% of sRGB on the galaxy tab 10.1 match the 94.4% on the ipad 3?

    http://www.anandtech.com/show/5688/apple-ipad-2012...

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