The Silicon - Meet the A4

Before the first iPad was ever unboxed, photos had already leaked of its dissection. Admittedly, I was relieved as it meant I didn’t have to risk destroying mine to figure out how to get inside the chassis. Why was getting inside Apple’s new tablet such a big deal? Because it’s using Apple’s brand new SoC.

It’s called the A4 because it is the 4th generation SoC designed by Apple. That would make the silicon in the iPhone 3GS the A3, the A2 would be what’s in the iPhone and perhaps A1 was an older iPod chip? Either way, the A4 was the first we heard of Apple’s naming system.

For months leading up to the iPad announcement everyone assumed that Apple’s acquisition of PA Semi meant that the company was going to ditch Samsung and come forth with its own killer SoC. Would it be an out-of-order Cortex A9 design? Or would it be truly custom, similar to what Marvell or Qualcomm have done with their Armada and Snapdragon lines?

As with everything involving the iPad, rumors of the device’s silicon ran rampant. But the idea of Apple doing their own microprocessor architecture for the iPad was disappointing to me. To understand why, we have to look at Apple COO, Tim Cook’s recent statements on why Apple has been successful:

“We are the most focused company that I know of or have read of or have any knowledge of. We say no to good ideas every day. We say no to great ideas in order to keep the amount of things we focus on very small in number so that we can put enormous energy behind the ones we do choose.”

Tim was talking about products there, but I believe his statement is applicable to the A4 as well. Apple is not a microprocessor company, nor does Apple want to toss its hat in with the likes of Intel, NVIDIA, Qualcomm and TI as an SoC maker. History has shown us that the only way to be a successful microprocessor company is to be able to subsidize the high cost of designing a powerful architecture over an extremely large install base. That’s why x86 survived, and it’s why the ARM business model works.

Designing high performance SoCs just for use in the iPad and iPhone just doesn’t make sense. In the short term, perhaps, but in the long run it would mean that Apple would have to grow the microprocessor side of its business considerably. That means tons of engineers, more resources that aren’t product focused, and honestly re-inventing the wheel a lot.

The fact that the A4 appears to be little more than a 45nm, 1GHz Cortex A8 paired with a PowerVR SGX GPU tells me that Apple isn’t off its rocker. I don’t exactly know what Apple is doing with all of these CPU and GPU engineers in house, but licensing tech from the companies who have experience in building the architectures is still on the menu.

The A4 is a typical smartphone SoC. It’s got CPU, GPU and DRAM all on a single package. It also appears to be the same size as your typical smartphone SoC, meaning there’s a good chance we’ll see this thing in the next iPhone. The A4 has 256MB of on-package DRAM, just like the current iPhone 3GS SoC. Remember that memory is used for the OS, all applications as well as video memory. It’s a testament to just how lightweight the iPhone OS is.

Rushed, the iPad Case & iTunes The iPad and its Performance
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  • vol7ron - Wednesday, April 7, 2010 - link

    There's been rumors the iPhone 4g will be talked about tomorrow by Apple. Do you have any insight into this?

    vol7ron
  • Griswold - Thursday, April 8, 2010 - link

    http://en.wikipedia.org/wiki/4g
  • vol7ron - Thursday, April 8, 2010 - link

    I don't understand the point of this link?
    Perhaps you want to look at: http://en.wikipedia.org/wiki/IPhone

    Data Network Technology and iPhone technology are not synonymous.
  • A5 - Thursday, April 8, 2010 - link

    Unless AT&T has suddenly deployed a 4G network (or they're going to Sprint), then this new phone isn't going to be called the iPhone 4G. Also, the stuff they're announcing tomorrow are the features of iPhone OS 4.0, not new iPhone hardware.
  • vol7ron - Thursday, April 8, 2010 - link

    I'd rather not hear about the hardware at this point, but it'd be nice to say that Apple would up the clock on the 3GS (what I have). Hearing about the OS 4.0 is nice.

    I thought the "G" has nothing to do do with the wireless technology network. While they both stand for "generation", Apple's iPhone/OS pair will still be called the iPhone 4G, regardless if it runs on 3G Network or CDMA technology, or if the OS is upgraded afterwards; if this is confusing, think about the iPhone 2G - it runs on the 3G network and can be upgraded to OS 3.0, but it is still a iPhone 2G due to the initial hardware/OS release.

    -----

    The developer meeting was actually quite nice. There were a few surprises, but nothing huge - just a bunch of much-needed updates :) There will more-than-likely be a few more OS4.0 goodies come June with the official iPhone 4G release.
  • Internet User - Thursday, April 8, 2010 - link

    That's incorrect. The naming conventions that Apple typically uses were thrown out the window. The first generation iPhone runs on the 2G EDGE network. The 3G (second gen) and 3GS (third gen) both run on the 3G network. We don't know what the fourth iteration will be called. It won't run on a 4G network, but it will be the 4G iPhone.
  • vol7ron - Friday, April 9, 2010 - link

    Perhaps you are right, but I thought I remember hearing Jobs talk about the naming that went into the iPhone.

    Technically, I think that what happened supports your argument, but we've all seen companies change their logical naming patterns. The first iPhone, as with any first generation, was called the "iPhone", with no suffixed 1G or 2G. It wasn't until the 3G came out (on OS 2.0), where there was question about its name. I think what was talked about was that the beta versions were considered 1G; the first retail release was considered 2G; and the second was 3G.

    The 3GS is where it really breaks that argument, because the 3GS was released with 3.0, so technically it would be called the iPhone 4G. Instead they stuck with the "3G" and added the "S", which they said stands for "speed". However, those "2G" phones that were upgraded to OS 3.0, still work with the 3G network, but are still considered "iPhone" (w/o the suffix, but still unofficially: iPhone 2G).

    In either case, I'm willing to say that I'm wrong, since a lot of it is vague memory. That, and the fact that this article is about the iPad and not the iPhone :) I was just a little curious about OS 4.0, but I was offered an exclusive direct link on the developers briefing, so I found everything out anyhow.

    vol7ron
  • nilepez - Thursday, April 8, 2010 - link

    I don't know about AT&T, but Verizon began testing LTE last year and is deploying LTE in some markets this year. Until Apple announces they're partnering with Verizon (or Sprint) or we see FCC submissions, I'll assume it's vaporware....and frankly, I'm not switching from my Sero plan for a phone.
  • vol7ron - Wednesday, April 7, 2010 - link

    Page 2: Since this isn't the 1980s, the iPad only has three four physical buttons on the device.

    I might be reading it wrong but the "three four" seemed out of place. Maybe that was supposed to be a "three or four", or perhaps you were going to come back to it?

    vol7ron
  • vol7ron - Wednesday, April 7, 2010 - link

    Page 5: "Tap it twice while you're playing music and playback controls appear, Also when..."
    Perhaps there should be a period where the comma is and a comma after "Also"?

    BTW, not purposefully checking for errors, just looking out for ya.
    vol7ron

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