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Apple A4 CPU Dissection: iPad is Just a Big iTouch

By - Source: Tom's Hardware US | B 62 comments

It uses the same sort of brains and brawn as the latest iPhone and iPod Touch models.

When Steve Jobs took to the stage earlier this year to unveil the iPad, he also announced a custom processor he called the A4. While the company has been rather mum on what's inside the package, early reports figured the A4 to be ARM-based, just like the iPhone and iPod Touch models. And they were right.

Teardown specialist firm iFixit sent the A4 chip to Canadian-based Chipworks, a semiconductor reverse engineering firm, for an x-ray and dissection to find out what Apple's chip is made up of.

These are the conclusions that iFixit it came to:

·  There's not much revolutionary here. In fact, the A4 is quite similar to the Samsung processor Apple uses in the iPhone [3GS].

·  It's clear from both hardware and software that this is a single core processor, so it must be the ARM Cortex A8, and NOT the rumored multicore A9.

·  It's quite challenging to identify block-level logic inside a processor, so to identify the GPU we're falling back to software: early benchmarks are showing similar 3D performance to the iPhone [3GS], so we're guessing that the iPad uses the same PowerVR SGX 535 GPU.

·  The iPad has 256 MB RAM, same as the iPhone [3GS].

·  The A4 sips power. In fact, power consumption is probably the reason Apple hasn't stepped up performance much from the iPhone [3GS]. In order to get 10 hours of battery life, the entire iPad (including display) has to pull less than 2.5 Watts on average.

It should be noted that, while both the CPU and GPU appear to be upclocked versions of the same things powering the iPhone 3GS, it's still impossible to tell at this stage. Furthermore, there is a single core version of the ARM Cortex A9, so Apple could be using a newer CPU than the A8 in the latest iPhone and iPod Touch.

Nevertheless, we agree with iFixit that, on a hardware level, "there's not much revolutionary here." Apple has essentially built a triple-layer, package-on-package custom chip using off-the-shelf components. Like the company does for the rest of its computing product, it takes something that's readily available in the technology marketplace and layers it with custom software to provide a markedly different experience.

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  • 25 Hide
    vaughn2k , April 7, 2010 3:05 AM
    "Apple A4 CPU Dissection: iPad is Just a Big iTouch"

    Damn right!
  • 24 Hide
    demosthenes81 , April 7, 2010 2:38 AM
    well duh!!!
  • 20 Hide
    vaughn2k , April 7, 2010 3:21 AM
    So much for the;

    "... While it may represent the most bleeding edge of a new technology..."
    http://www.tomsguide.com/us/ipad-wifi-wi-fi-overheating-wireless,news-6360.html

    ok, now it bleeds with crap alright...
Other Comments
  • 24 Hide
    demosthenes81 , April 7, 2010 2:38 AM
    well duh!!!
  • 0 Hide
    dannyaa , April 7, 2010 2:57 AM
    Yeah why didn't anyone listen to DAWGSOVERREBS??! Gosh! He has been saying this for a while and the whole internet ignored him! Everyone really ought to get some common sense and be sure not to make that mistake again!
  • 25 Hide
    vaughn2k , April 7, 2010 3:05 AM
    "Apple A4 CPU Dissection: iPad is Just a Big iTouch"

    Damn right!
  • -4 Hide
    liquidsnake718 , April 7, 2010 3:08 AM
    if it cant play a simple game like cod 3 then it is a crapper.... can it play something like HL2? Now then it should be a "benchmark" for a meager system like this.... then again netbooks cant either....
  • 20 Hide
    vaughn2k , April 7, 2010 3:21 AM
    So much for the;

    "... While it may represent the most bleeding edge of a new technology..."
    http://www.tomsguide.com/us/ipad-wifi-wi-fi-overheating-wireless,news-6360.html

    ok, now it bleeds with crap alright...
  • 2 Hide
    invlem , April 7, 2010 3:36 AM
    In apple's defense they really havent been hiding that fact, I mean really, It's looked like an iTouch on steroids since day one :p 
  • 14 Hide
    tinmann , April 7, 2010 3:47 AM
    The AFBS (Apple FanBoys) are eerily silent. I was on another site and it was ablaze with praise for the iPad. They were toting it as the best thing since the wheel. Computing for the masses.....Computing!!! What a joke.
  • 15 Hide
    HansVonOhain , April 7, 2010 3:54 AM
    Can it play Java? that is the new question. :p 
  • 9 Hide
    mdillenbeck , April 7, 2010 3:57 AM
    vaughn2kSo much for the;"... While it may represent the most bleeding edge of a new technology..."http://www.tomsguide.com/us/ipad-w [...] -6360.htmlok, now it bleeds with crap alright...

    Oh, come now - you can't hold Tom's to that old post. That was posted 86,400 seconds before this one! You know that technology never sits still. (Hope Tom's can take a joke...)

    -------------------------------

    dawgsoverrebsI HAVE BEEN SAYING THIS SINCE BEFORE THE FREAKIN ANNOUNCEMENT CEREMONY PARADE HOLIDAY THING THEY HAD.

    Um, you weren't alone... and yet how many times here on Tom's have we been told "its not just a giant iTouch... its something new called a 'tablet'". *rolls eyes*

    ------------------------------

    I wonder if this news will also make Tuan reconsider What HP Needs for Slate to Take on iPad, and Win, or more accurately if Taun is willing to consider that the HP slate falls in the netbook classification while the iPad does not... thus it is like trying to compare netbooks to laptops, or laptops to desktops.

    ---------------------------------------

    Does this news, or the news of weak wi-fi and overheating mean my predictions that people will continue to snap up iPads in an Apple buying frenzy to feel young and hip and cool? No.

    Read the book No Logo, and you'll understand that most companies you recognize by name are dropping manufacturing (these require assets, which require liabilities to acquire and run... you know loans for a building and those things called employees) in turn for "branding".

    I say this with the greatest respect, Apple has truly mastered the fine art of branding. Were there better mp3 players out there? Were there better smartphones out there? (Consider price point also.) Was their commercial campaign deceptive when comparing their proprietary software and hardware system to the leading operating system software? Did Apple capture an image that their products equal youth, rebellion, hipness, sharp wits, cool, sassy, etc? I think yes.

    Either way, I am so sick of the iPad - both the pro- and con- sides... I kinda wish the pro side would say "yeah, it isn't new and revolutionary, but I like it" and the con side would say "glad its working out for you, enjoy".
  • 2 Hide
    tipoo , April 7, 2010 4:46 AM
    Single core Cortex A8, 256MB of RAM. Disappointing, a smartphone like the Nexus One or HD2 even out-specs it.

    Good thing the Courier will have that juicy Tegra 2 with dual core Cortex A9 goodness, eh?
  • 2 Hide
    ps12 , April 7, 2010 5:04 AM
    ...As if this wasn't confirmed before.
  • 7 Hide
    Anonymous , April 7, 2010 5:10 AM
    Tayb, you write that "It's the experience they can squeeze out of that chip that matters." That's true, but you only have one half of the equation. Sure, the iPad's snappy, but that's because it's a glorified PDA. I'll take my netbook and its "experience" -- full keyboard, Linux support, ability to install damn near whatever I want -- and you can keep the iPad's snappiness with free-websites-turned-into-pay-product "apps."
  • -8 Hide
    Anonymous , April 7, 2010 5:14 AM
    No credibility in this article. For one thing there is no such thing as an 'iTouch'
  • 0 Hide
    OvrClkr , April 7, 2010 5:16 AM
    I say its a big touch, nothing more..
  • -9 Hide
    vaughn2k , April 7, 2010 5:17 AM
    Quote:
    Oh, come now - you can't hold Tom's to that old post. That was posted 86,400 seconds before this one! You know that technology never sits still. (Hope Tom's can take a joke...)



    Wrong dude. Technology may sit still within 24 hours (or 86,400 seconds as you may say) but ideas don't.
    Implementation may take 4 to six months or so.

    You're definitely wrong.
  • -2 Hide
    tayb , April 7, 2010 5:21 AM
    Well, as an ex-netbook owner I can say that the netbook experience is far from ideal and most of the time is in fact absolutely awful. You get better hardware on a netbook but it's not nearly enough to run Windows 7. 1.6GHz Atom, 2GB of ram, and ION look great in comparison to iPad specifications but the actual user experience is terrible. Slowdowns slowdowns and more slowdowns. That doesn't even mention the cramped keyboard, damn near unusable touchpad, and pathetic battery life. I suppose if you ran a variant of Linux the performance hit wouldn't be as bad but no software is going to fix the hardware failures that plague every netbook I've tried and if we are talking about Linux we are still discussing limited software availability just like the iPad.

    The chip in the iPad does what it is supposed to do. Runs the UI without slowdowns and provides great battery life. Why would Apple ramp up the clock speeds when they have nothing to gain from it? The interface won't be any snappier with higher clock speeds.

    I didn't see a market for netbooks and still don't quite understand the demand. I don't really see a market for the iPad but I know it too will sell well.
  • 3 Hide
    eddieroolz , April 7, 2010 6:30 AM
    Meh. Do not care, do not want.
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