First, two quotes from my review of the original iPhone:

“The issue is that the iPhone interface is just as responsive as a computer, so you inherently expect the sort of performance you'd see on a notebook and it's just impossible on a device like the iPhone."

“I think overall we need a handful of upgrades to the iPhone alongside 3G; we need a faster processor, possibly more system memory, maybe even faster flash. The MLC flash in the iPhone has absolutely horrendous write speeds compared to SLC, which could be holding the iPhone back a bit. I can see Apple introducing a 3G version in about 12 months, addressing many of these issues at the same time.”

Indeed, 12 months after the launch of the first iPhone - Apple did fix the wireless performance issues with the iPhone 3G. Unfortunately, the hardware remained untouched. All of my other complaints in those two quotes remained open ticket items between Apple and I. In fact, things got worse. Here we have what I wrote at the end of my iPhone 3G review:

“Apple must be wary of the direction the iPhone is headed in. While the UI was absolutely perfect for the phone that launched a year ago, today’s iPhone is hardly the same. With easily over twice as many applications on an iPhone today vs. a year ago, performance and navigation have both suffered. The impact isn’t tremendous, but Apple will have to adjust the iPhone accordingly in order to avoid turning the platform into a bloated, complicated mess.”

Two days ago, Apple announced the iPhone 3GS - designed to address one thing: performance. The other half of my complaint in the conclusion of my 3G review, addressing navigation and UI with the new expanded iPhone platform, isn’t addressed by the 3GS. I suspect that in another year we’ll see that. But today, it’s about hardware.

The Impetus

After yesterday's Pre vs. iPhone 3G battery life article I got a few emails from people very close to the chips used in the iPhone 3GS. A couple of exchanges later and I realized it might be time to go a little deeper with the hardware behind the iPhone 3G, iPhone 3GS and the Palm Pre.

The Original

The iPhone and iPhone 3G use a system on a chip (SoC) from Samsung. The SoC is a custom part and actually has Apple’s logo on the chip. The SoC houses the CPU, GPU and memory for the iPhone.

The CPU is based on the ARM11 core, in specific it is the ARM1176JZF-S. The CPU runs at 412MHz to save power, although the core is capable of running at 667MHz. The ARM11 CPU is a single-issue in-order microprocessor with an 8-stage integer pipeline. It’s got a 32KB L1 cache (16KB for instructions, 16KB for data) and no L2 cache. The ARM11 CPU in the iPhone also has a vector floating point unit, but thankfully the SoC includes a separate GPU for 3D acceleration. You can think of this core as a very high clocked, very advanced 486. And extremely low power. Under typical load, the CPU core should consume around 100mW. By comparison, the CPU in your laptop can require anywhere from 10 - 35W. Idle power is even lower.

Paired with this CPU is a PowerVR MBX-Lite GPU core. This GPU, like the CPU, is built on a 90nm process and is quite simple. The GPU does support hardware transform and lighting but it’s fully fixed function, think of it as a DirectX 6/7 class GPU (Riva TNT2/GeForce 256). Here’s PowerVR’s block diagram of the MBX:

The MBX-Lite in the iPhone shares the same architecture as the MBX but is optimized, once more, for power efficiency and thus is significantly slower.

I don’t have exact clock speed information for the MBX-Lite in the iPhone but I’m guessing around 60MHz.

Coupled with the CPU and the GPU in the iPhone’s SoC is 128MB of DDR memory, all on the same chip. It’s a pretty impressive little package. You get a CPU, GPU and memory all in a package that’s physically smaller than Intel’s Atom.

Now the 486 came out in 1989 and the original 3dfx Voodoo graphics card came out in 1996. The iPhone’s SoC would be ridiculously powerful if it were running the sorts of applications we had back then, but it’s not. We’re asking a lot from this little core and although it has performed admirably thanks to some clever software engineering on Apple’s part, it’s time for an update.

Enter the ARM Cortex A8
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  • araczynski - Monday, June 15, 2009 - link

    blah blah blah same crappy gameboy resolution screen blah blah blah talk to nokia blah blah blah.

    maybe if half the price of the stupid thing went into the device instead of paying for all the worthless marketing they'd have a killer device that i would gladly pay $130 a month for for unlimited data service.

    ah well, maybe in a few years.
  • punkball - Saturday, June 13, 2009 - link

    I dunno why ,i have a good feeling
    not knowing much at all about (only what seems to be a negative
    evaluation on parts; by the community).
    This phone its main uphearst performace being, we'll see a comprised Flash/Flex player on the iTunes store ?a good deal onwards agreed on a Mac-device friendly version of the Flash Player?? Anyone else hoping/caring?
  • lateef - Friday, June 12, 2009 - link

    does anyone know if the radio/wireless chipset been upgraded in the 3gs rather than a tweak
  • iwodo - Friday, June 12, 2009 - link

    Arh, interesting question. I think everyone were too concentrated on its CPU, Memory and GPU and forgot the most fundamental / important issues.
    To be honest iPhone is rather weak for its Radio Reception. I think this is partly due to Infineon are new to Mobile Chipset.
    Is there an updated chipset to fix iPhone Comparatively poor quality reception?
    ( Last time i heard the 7.2Mbps speed increase has to do with Firmware unlocking, so i am not sure if the chipset has been updated )
  • PhilipOrr - Friday, June 12, 2009 - link

    Was talking with the Apple engineers at WWDC which technical data sheets to look up concerning the GPU within the new iPhone. It's the PowerVR SGX 535.

    This chip is one up from the Palm Pre which is the PowerVR SGX 530.

    The difference between these is more video based than anything else. 535 has hardware acceleration for H.264 encode/decode, MPEG 4 and JPEG. It also handles HD content to 720p in real time.

    These specs seem to give a hint to what Apple are planning for future upgrades of the iPhone or other device. Suggesting, that if your developing for the 3GS then you're already developing for the next generation too.
  • jasaero - Friday, June 12, 2009 - link

    My guess is that the 535 was used more for optimizing the video option on the phone than for any future planned uses. Not required to do video, but is extremely useful in reducing file sizes of video output and may help with some of the video editing functionality it supossedly has. So far Apple hasn't really preplanned any added functionality so much as reacted to demand for certain features they seemed to have left out useablity and performance trade off. Copy, cut, paste being the most glaring example. Basically I am quite doubtful they have a handset like the Omnia HD that probably uses this same chip in their sights just yet.
  • iwodo - Thursday, June 11, 2009 - link

    I really hope anand do some detail article on Mobile Tech. MIPS, ARM, difference between ARMv6 and v7. SnapDragon and OMAP. I mean if iPhone uses a SOC that is 90% the same as TI's OMAP, why not just buy it from OMAP? Do different implementation of ARM matters? How does Tegra compare to SGX, what about Mani ( ARM ) 's graphics department?

    There are about 10 dozens more questions i hope anand could answer. The truth is, as a tech news reader, i haven't been as excited as this for a long time. PC are already way too powerful then 90%+ of our needs. That is why Netbook are so popular. They are cheap, and gets the job done.

    The next battle, and most interesting development in the next decade will be on Mobile front. Where ARM and PowerVR dominate. PC tech are used to Intel and ATI/Nvidia so ARM and PowerVR's tech are Alien to us.

    I really hope there will be more in depth article about Mobile Technology. The only thing that interest me in PC is development of SSD.
  • Anand Lal Shimpi - Friday, June 12, 2009 - link

    I've been dabbling in it for a while but I think I agree with you. Such a comparison may be necessary. I'm going to start chasing some of these technologies and see where I end up. If I find something sufficiently interesting, I'll be sure to share :)

    Take care,
  • iwodo - Friday, June 12, 2009 - link

    Thanks. Hoping for more ARM info soon.

  • AnnonymousCoward - Friday, June 12, 2009 - link

    I agree. Apple should be buying OMAP instead of the ASIC. I think digital camera companies will be going that route too.

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