The A9X SoC & More To Come

Finally, as everyone is undoubtedly eagerly anticipating our look at the A9X SoC inside the iPad Pro, let’s take a very quick look at what we know about the SoC so far. There’s a bit of a limit to what we can do blindly via just software, but I’m hoping that the eventual A9X die shots will confirm some of our suspicions on A9X’s configuration.

Apple SoC Comparison
  A9X A9 A8X A6X
CPU 2x Twister 2x Twister 3x Typhoon 2x Swift
CPU Clockspeed 2.26GHz 1.85GHz 1.5GHz 1.3GHz
GPU PVR 10 cluster Series7? PVR GT7600 Apple/PVR GXA6850 PVR SGX554 MP4
Memory Bus Width 128-bit 64-bit 128-bit 128-bit
Memory Bandwidth 51.2GB/sec 25.6GB/sec 25.6GB/sec 17.1GB/sec
L2 Cache 3MB 3MB 2MB 1MB
Manufacturing Process Unknown
(TSMC 16nm or Samsung 14nm)
TSMC 16nm &
Samsung 14nm
TSMC 20nm Samsung 32nm

First and foremost, the most unexpected news here is that unlike A8X, A9X is not packing a triple-core CPU. Instead A9X drops back down to just a pair of Twister CPU cores. The twist here is that relative to A8X and A9, Apple has cranked up their CPU clockspeeds. Way, way up. Whereas the iPad Air 2 (A8X) shipped at 1.5GHz and the iPhone 6s (A9) at 1.85GHz, the A9X sees Apple push their clockspeed to 2.26GHz. Not counting the architectural changes, this is 22% higher clocked than the A9 and 51% higher than the A8X.

The fact that Apple dropped back down to 2 CPU cores is unexpected given that we don’t expect Apple to ever go backwards in such a fashion, and while we’ll never know the official reason for everything Apple does, in retrospect I’m starting to think that A8X was an anomaly and Apple didn’t really want a tri-core CPU in the first place. A8X came at a time where Apple was bound by TSMC’s 20nm process and couldn’t drive up their clockspeeds without vastly increasing power consumption, so a third core was a far more power effective option.

WebXPRT 2013 (Chrome/Safari/IE)

Basemark OS II 2.0 - Overall

By comparison, with the FinFET process Apple is using here – and given the lower volume of A9X I don’t have reason to believe it’s dual-sourced, so it’s either TSMC or Samsung – Apple has been free to increase their clockspeeds substantially. At the same time these FinFET processes are still new and yields won’t be great, so there is a strong incentive to keep die sizes down to keep yields up, and adding a third core would only make that harder. If I had to guess, Apple only wanted two cores to begin with – this makes it easier for developers knowing that they only have two cores to work with – and that it’s A8X that is the anomaly.

Otherwise a highly clocked CPU is far more in-line with Apple’s design philosophy as it means that A9X is capable of amazing single-threaded performance – and keep in mind that we’re talking ARM Cortex-A57-like clockspeeds for a CPU that gets much more work done per cycle – so what we see here makes a lot of sense. Plus with iPad Pro in particular Apple has more battery capacity to sustain the power draw of a higher clocked SoC, and more surface area to dissipate that heat, so the usual concerns about power and cooling aren’t quite as pressing. I do wonder if this will impact multitasking performance much, but given what Twister is capable of, I’m not nearly ready to write off a dual-core Twister implementation clocked this high.

Moving on, as is customary for the X-series SoCs from Apple, A9X features what I believe to be a wider 128-bit LPDDR4 memory bus. The memory bandwidth numbers clearly point to a wider bus, and Apple needs the bandwidth to feed a more powerful GPU.

Geekbench 3 Memory Bandwidth Comparison (1 thread)
  Stream Copy Stream Scale Stream Add Stream Triad
Apple A9X 2.26GHz 20.8 GB/s 15.0 GB/s 15.3 GB/s 15.1 GB/s
Apple A8X 1.5GHz 14.2 GB/s 7.44 GB/s 7.54 GB/s 7.49 GB/s
A9X Advantage 46.4% 101% 103% 102%

Which brings us to the last bit of our preview, the GPU. Apple went with a 6 cluster PowerVR Series7 design on A9, and for A9X they have gone with a larger design. Without a die photo it’s basically impossible to determine how many clusters are in use since clockspeed plays such an important role. What we do know is that GPU performance relative to A9 has pretty much doubled, which once again is right in-line with Apple’s usual design goals.

GFXBench 3.0 Manhattan (Offscreen)

Given what Apple has done with clockspeed on Twister, for the moment I am staking my bet on it being a 10 cluster design with a higher GPU clockspeed than A9 giving us the rest of the performance boost. To be clear here this could also be a 12 cluster design at a similar clockspeed or even an 8 cluster design clocked far higher – we’ll need die shots to confirm – but given all of the options it’s a 10 cluster design that is the best balance between die size and clockspeed, and it would also be the biggest curveball Apple could throw. It should also be noted that PowerVR Series7 certainly supports such a configuration since it’s scalable from 2 to 16 clusters, although in Imagination’s official product catalog they don’t have a name for such a configuration. So for the moment I’m simply calling it a 10 cluster Series7.

Anyhow, we’ll be back later with a full review of the iPad Pro, including the pros and cons of Apple’s first large-format, productivity-oriented tablet, and a full breakdown of the A9X SoC. So until then stay tuned.

Taking Notes With iPad Pro
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  • witeken - Wednesday, November 11, 2015 - link

    The manufacturing process of the A9 is wrong.
  • Ryan Smith - Wednesday, November 11, 2015 - link

    And this is what I get for copying tables at 3am in the morning. Thanks!
  • tempestglen - Wednesday, November 11, 2015 - link

    Thanks for your quick preview!
  • Der2 - Wednesday, November 11, 2015 - link

    This review going to be awesome!!!
  • close - Wednesday, November 11, 2015 - link

    How were the 4 SoCs in the table on page 2 chosen? A9X, A9, A8X, A6X. Basically iPad Pro, iPhone6s(Plus), iPad Air2, iPad4.

    Maybe I'm missing something but what were the criteria when these 4 were chosen for the Apple SoC Comparison? Why not A7 for example?
  • extide - Wednesday, November 11, 2015 - link

    A9X -- obvious
    A9 -- phone version of above
    A8X - previous tablet/x series soc
    A6X - next previous X series soc
  • Ryan Smith - Wednesday, November 11, 2015 - link

    The above is basically correct. I purposely picked the two previous X-series SoCs, and then the phone version of the A9 family.
  • dsumanik - Thursday, November 12, 2015 - link

    Pfft, i see Joshua Ho has his nice grey carpet background out in full force to promote yet another apple product to the max....hey Joshua. Why do ONLY apple products only get this special treatment/photoshopping/product arranging.... Also you forgot the nice picture of the product held niceely in front of the clean leafy tree?

    20 bucks says that will be the review's opener image.
  • akdj - Saturday, November 14, 2015 - link

    Dsu(data service unit?)manic,
    I'm not sure we're reading/viewing the same website. While the pencil shot looks cool in my opinion too (you've seem to had your mind blown!) ...its no different than any product line I've seen reviewed over the last decade. It's simple, easy implementation of some basic rules of photography direction of flow, attention on subject ...and when not overtaking the subject, a killer background that makes said subject pop off the page.
    You're not very familiar with this century's version of Photoshop --- if you believe this '(sic) apple (notice, without a capital A) product only gets this special treatment/photoshopping(again)/product arranging'. That's delusional. Most great shots --- certainly historical, but even current well known and respected pictures made have little to zero done with PS. And everything to do with the photographer. Zero to do with the lens. Body. Even subject. ALL to do with the photog

    Case in point. Lay pencil on trippy, same line flow, multi colored Berber? Burber? Too lazy to look carpet. Snap shot with any camera phone laying around. Crop in cam. Email me-self. Done. And you think it deserves a Pulitzer?
    Josh, my sincere apologies I love your site, the way you write and enjoy visiting throughout the week. But apparently this Data Service Unit Manic (just draws a funny picture, like the poster thinks he ((not she, ladies are too smart for some of us here!)) is the singular gatekeeper of knowledge between the 'Matrix' (en/transcoding - hence the only "one" with 100%, true knowledge and ability to manipulate either side to their own favor) and the real world.
    ...or he/she went to Delaware State University. Hmmmm. Ponderous ...but one must as oneself, how much more relevant a review of the latest NAS, motherboard, or PCIe storage systems using nVMe would be with 'specially treated/photoshopped/arrangement of said PCIe controller or storage array
    That's. Just. Dumb. A nitpicking, no life comment that should be ignored but being on top the stack, I've wanted to poke you in the eye all week. It's a F'ing pencil on the carpet. I'm too lazy to strip Josh's metadata. Even if he left the hardware and shot info intact, it's these buffoon type comments that have destroyed the 'comment section' here at Anand. I bet I read 225 comments without ANYTHING to do with the iPhone 6s6s+ review before coming across anything interesting.

    Apple is pushing the boundaries in real ways with the very few, focused and aggregating/integration systems of continuity and Handoff. Horizontal and vertical support to your like. Personally, professionally from your health to your wealth to your physical being. No one saw 'This' coming in 2015. I used 'tablets' (I'm a pilot, have been for 27 years) in 2005. I used 'smartphones' in '05. Sounds like such an oxymoron now as those tablets were monochrome, specific to certain tasks, bulky and boring. Smartphones, that's what they were. We've long since past this even being considered a 'phone' first any longer. It's a tertiary ability amongst an entire sea change of computing, unlplugging from 110v and enjoying connectivity faster than broadband, speeds faster than yesterday's full - 2/4/8 core lappies with storage subsystems and speeds that massacre what most use 'on the desk'. They're our window to the world. News. Email/messaging/comms. Social and sports, lifestyle and calculator, dayplanner and Rolodex! Lol. I'm dating myself. They're displays smoke what we paid $5k for a short decade for, packing twice the pixels into a few ounces and lasting a full day!
    Smart wearables. Look at the industry. Catch wind 'Apple's gonna do it'. Rush to get half assed, overpriced underperforming wannabes out the door before Cupertino. Apple, being Apple intelligently bides their time. Gets the Apple Watch right in so many ways - opens the doors and outsells the competition in aggregate and in a weekend (vs. 500-1,000 days/3 years)!!!

    That's what I dig about Apple. Their products. Both soft and hardware as well as their services. I did spend two decades on PCs. I started on a IIe in '83 playing MS's Flight simulator. Ten years ago, +/- I was smart enough to listen to my wife. Buy her a MacBook as a graduation gift, she'd finished her doctorate. Haven't looked back

    ..the guy that sold me the machine's name was Earnest. I called him a couple days later ...frustrated to no end after two days searching for the add/remove control center populater. And with that, the ability to uninstall a piece of software I didn't want. He got on the phone. Told me to click, drag to the garbage can (not recycle or trash, he said its garbage if you're done with it), empty garbage.
    That was the second time he told me he'd see me in a week to sell me mine. He was right. Apple is building real tools ...maybe, and sometimes arguably existing technologies that no one uses but niche or proprietary OEMs. Then they re-form, re-build, tool, and release completely disprupto get world economies. See cell phone sales pre 2007/08/09 and today. See computer sales a decade ago, compare to iPad and increased quarter after quarter computer sales growth (rest of industry down), and a 'phone' (pocket computer) that blows through every previous tech sales record each year it's released! They're 'hobby' is capable of sustaining a position on the Firbes 500 (Apple TV) itself, while iTunes would alone be in the top 50!!

    iTunes, the bloated pig it was when I ripped 2800 songs in 20p02 to my monochrome 20GB iPod from Costco was a PITA. Maybe it's the speed of my rMBP today, or the deconstruction and rebuild of iTunes both iOS (separated between each; music, video, podcasts) or AiO --- there's nothing on the planet that comes anywhere close to such exceptional media management. I use PLEX server at home for a ripped/streaming video server but it's fed through Apple TV. I can pause my show from my watch or phone or tab, finish the email I'm writing while my morning 'rest stop with coffee' and if not, too into an article... It's automatically on my desk when I'm 'done'.

    Apple is somewhat a victim of their own doing. I own every iPad with exception of the 'new' iPad 3. Had it. Sold it. Bought the iPad 4 when it dropped. We use Mini, now 4s in all three cockpits and started with the mini 2. For me, my colleagues it's a game changer. Replacing 55 pins flight bags that are constantly updating charts, plates, obviously weather an traffic and NOTAMs, restrictions and flight patterns.
    Fuggedaboutit. Flight planning to fuel loads. Diversion strips to Jep charts, up to date plates weather - real time traffic and terrain and every manual checklist and procedure at my fingertips. True. Game changing. Technology

    And now the 'Pro'. An unprecedented decide for the creative. Crushing it's 'competition' with the weight of another way of thinking. Wacom was selling their tabs for thousands of dollars just two years ago. Still needed a PC to use it too! The surface pro is finally getting there, though much to be desired for tablet use and battery life.
    Where iOS is already ripe and rich with apps software and tools to take advantage out of the gate. Autodesk Adobe, even Microsoft are dedicated MORE resources today than ever in history to mobile development of the their software --- in some rumors, more than ½ of the development teams efforts have shifted ...
    ....with the sea change Apple began in 2007 with an iPhone I've still got. Looking at v1 iPhone and iPad along side the 6s/6s+ and iPad 1 v iPad Air 2/pro v1 it's amazing to see what a ½ decade and eight years have allowed

    ...we've benefited in our lives everywhere you can name. Including the most significant decade of change in automotive in a hundred years (before we had cars!) and the amazing inter connectivity, GPS, comms and computing, thanks to Apple, Google, Samsung and companies like TSMC. Our braking systems are light years ahead of the first anti lock systems. Traction control and sensors like accelerometers, barometers and proximity sensors, same as phones and tabs. HiDPI and visible in sunlight displays --- even our vehicles have transformed 2005-2015!!! And in no small way

    Yet you're up in arms about a cool shot (excellent photo Josh) of a pencil that's on carpet? Hmmm. Happen to 'read', not just look? Low enough latency, it's a non issue on a v1 device? Awesome resolution, phenomenal, laptop --- current generation compute power and class tripling graphic and NAND performance, this very well COULD be a laptop replacement for a huge section of society

    Remember --- Adobe, MS, AutoDesk, IBM ...Mari for crying out loud! The one and final reason we've had to maintain a fast Win rig. No. More. Developers alike are flocking to the very lucrative business model for iOS and OS X development to continue refining complete and pure workflow. Whether our watch, our phone, tablet or home computer, the seamless integration and continuity is unrivaled --- without end in site!
    Android, they don't have a prayer. Tabs are years behind with an eco system and they're without anything but connection dependent chrome books
    Windows, if they get this Win10 'thing' right, I see being the only true competition to what Apple's managed to create. And that's a 5-10 year plan as its playing out

    Sheesh. Didn't think I could write a novel about a pencil on the carpet was all in the manic Matrix gatekeeper and his goofy response. Sorry.

    Too long? Don't read
  • casperes1996 - Sunday, November 22, 2015 - link

    Thank you for not being a cunt. I agree with 80% of what you said, maybe more. And you did it in a fine way.

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