The Hardware

Leading up to today’s announcement I desperately tried to figure out what hardware Apple would use for the iPad. I’ve been on a bit of an SoC kick as of late, so you can understand my fascination.

Apple acquired PA Semi back in 2008. Everyone assumed that it’s because Apple wants to start making its own SoCs for the iPhone. Well, the first results of that acquisition are in the iPad.

Apple didn’t devote much time to the SoC in the iPad other than to tell the world that it’s Apple’s own silicon and it runs at 1GHz. The SoC is called the A4. I’ve asked Apple for more details on it, but I’m not holding my breath for a response.

Given the fact that it runs the iPhone OS and nearly all iPhone apps, I’m guessing the A4 is ARMv7 based. It’s possible that Apple engineered its own architecture for the A4, but more likely that it simply took an existing ARM design and modified it to suit its needs.

If Apple wanted to save cost it would’ve gone with a Cortex A8 based processor, or if it wanted more performance it would be something more A9 like. I’m not ruling out a dual-core implementation, but given the entry level cost point I’m assuming that it’s not anything quite as fantastic.

The 1GHz operating frequency implies a 45nm manufacturing process if it’s indeed an A8 or A9-like core. If we look at Apple’s public video, it appears to render a page at Spin.com in roughly 2.7 seconds. My iPhone 3GS does the same in about 7 - 9 seconds, but it also appears to be loading a lot more content on the current Spin.com site. Even if we assume that the 600MHz Cortex A8 in the iPhone 3GS can render the same page in 5 seconds, the speedup is too big to be from a clock speed increase alone.

Based on this data alone (and the responsiveness of the UI from the videos) I’m going to say that there’s a good chance that the A4 is much closer to the A9 in terms of performance. If it’s not an A9 itself, it may be Apple’s own out-of-order design.

Then there’s battery life. Apple is claiming 10 hours of web browsing battery life, which is reasonable given the 25WHr battery, but over a month of standby power. I suspect that the ridiculous standby power is due to the fact that the 3G radio is completely shut off when the device is asleep, but even then that’s very good power consumption. If anything, Apple’s own engineering here was probably spent on making sure that the SoC’s power consumption was as low as possible. By comparison, even the best SoCs in a smartphone today can usually only offer 300 hours of standby power (12.5 days).

Apple’s battery life claims have been unusually reliable as of late, so I would say that we should expect 10 hours of useful battery life out of one of these things.

I’ve spent a lot of time talking about the CPU, but what about the GPU in the A4? Given that Apple is a shareholder in Imagination Technologies (9.5%), I’d say that it’s a pretty safe bet to assume there’s some sort of a PowerVR SGX core in here. Which core? There’s definitely the physical space to include something ridiculous, but I’m guessing it’s something relatively controlled - perhaps an SGX 535 or SGX 540 at the most.

A4 in the next iPhone?

I've been racking my brain over the past several months trying to figure out what Apple will use in the next iPhone. I figured it could be as simple as a 45nm Cortex A8 shrink, or as ridiculously sweet as a pair of Cortex A9s. With the iPad being based on Apple's own A4 SoC design, I'm guessing we'll see it (or a derivative) making an appearance in the 4th generation iPhone.

Will it Work...Literally Resolution, Video Decoding & Final Words
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  • autoboy - Wednesday, January 27, 2010 - link

    I've got a powerful notebook connected to real monitors I take between home and work, my blackberry on the go, and my netbook around the house and when I'm traveling.

    Yes the netbook sacrifices performance while traveling, but it is a full PC when I need it, and a long lasting casual web browser when I'm on the couch. Because the iPad is just an upscaled iPhone, it will never be able to replace my notebook while traveling. The netbook can. So, instead of carrying a heavy notebook with limited battery, my phone, AND a iPad for casual entertainment, I can carry just my phone and my netbook while only losing a bit of all out performance.
  • NullSubroutine - Wednesday, January 27, 2010 - link

    I'm going to have to agree with you about wondering this is going to fit in peoples lives. Personally I have a powerful desktop and a once top of the line 17" laptop, I don't have a smart phone or such device as I don't travel or move around all that much, nor do I have a workplace that would sync will with it.

    I do have a PSP (slim 2000) I use for occasional trips, so I can watch movies, listen to music, or play some games. For me this device could be something that could fit well because I don't have a very mobile laptop nor a smart phone.

    However it doesn't take the place of my portable media device, as it doesn't watch movies outside of the iTunes store, and can't display its graphics to a larger screen (like a laptop could). To me this devices sacrifices far too many qualities (really it is versatility) with low end laptops or net books while not really enhancing what current things do. It really is just a bigger screened iTouch/iPhone, which really doesn't appeal to me.

    What this needs is more multimedia capabilities. More connections, ports, software support (or allow developers to add more) for file types, and playback of something more than just 720p content.
  • ltcommanderdata - Thursday, January 28, 2010 - link

    If it's anything like iPods or iPhones, then multimedia content doesn't have to come from the iTunes Store. It should be able to play non-iTunes Store music or video although some re-encoding might be necessary.

    The iPad now actually has officially sanctioned external monitor capability as part of the SDK from early reports. You'll need the proper cable to connect to the dock though.
  • OBLAMA2009 - Wednesday, January 27, 2010 - link

    the tablet format does have some appeal for internet surfing. just not having to fold a laptop open makes you more likely to use it for light surfing. but it still needs mobile wireless and a faster boot up
  • OBLAMA2009 - Wednesday, January 27, 2010 - link

    o phuck they are offering att wireless 3g for 15 a month or 30 unlimited. that is a pretty good deal. maybe this thing will sell, but ill still wait for the ipad s version
  • deputc26 - Wednesday, January 27, 2010 - link

    Given it has 20.833x the battery capacity of the iPhone, I'm going to go ahead and guess that the IPS screen is a huge e- hog. Especially if speculation that the A4 is a 45nm single-core chip is correct. (and Apple would have said if it was dual core I think). Waiting for the OLED model with 15hr bat life.
  • deputc26 - Wednesday, January 27, 2010 - link

    Edit: Nice write up Anand, exactly what I was hoping you'd cover, really just verified I hadn't missed anything, the SOC was the big question for myself as well.
  • autoboy - Wednesday, January 27, 2010 - link

    Agreed. Thanks Anand. Always a pleasure to read your opinion. But, I have to disagree somewhat. This post was really easy on my netbook while listening to pandora and editing my word documents.
  • gusc3669 - Wednesday, January 27, 2010 - link

    The product seems to have potential (in future versions, perhaps). While this may appeal to couch potatoes everywhere (myself included), without actually seeing in its full glory, it seems too much like an expensive, high-end netbook. Perhaps it will be able to run some better apps once they are designed for it or be used instead of a textbook in classes. I'll just have to wait (a few years) and see.
  • Lonyo - Wednesday, January 27, 2010 - link

    There's a just under $500 Netbook out there called the Asus Eee T91.
    It's a netbook, but its also a tablet.

    Given that the $500 price point is hittable by existing netbook tablets which run a full OS with multitasking capability, it doesn't really seem unreasonable that going forward there will be more products in this class.

    Also with the one month standby time, I expect my regular laptop might be able to get close to that with Windows Vista or Windows 7. Using hybrid sleep they can wake up instantly from sleep mode and be instantly ready. I would assume that a function like that would be workable into the iPhone OS for the tablet, and basically have a similar function.
    Given the fact that it doesn't really need to be on, unlike a phone which needs to be ready to take calls etc, it seems like an off bt with power to RAM type mode would make sense to give tremendous standby time.

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