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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  • sxr7171 - Wednesday, June 10, 2009 - link

    A Dreamcast in the palm of your hand. Please port some Dreamcast titles to this phone. I would order mine this minute.
  • squngy - Wednesday, June 10, 2009 - link

    So how would these systems compare with the PSP or DS?

    If we're talking about games, then it would make sense to know where it stands compered to other popular gaming devices.
  • Anand Lal Shimpi - Wednesday, June 10, 2009 - link

    Compared to the DS, the iPhone 3G (and 3GS) are both way more powerful. That thing uses an ARM9E based processor and runs at no more than 133MHz I believe. The Cortex A8 should run circles around it. According to Wikipedia, the DS' "GPU" can reach a peak of 120K triangles per second...the first iPhone is capable of 1M per second. The iPhone is a superior hardware platform from a specs standpoint.

    The PSP is a bit more difficult of a comparison. It's got two MIPS cores plus a GPU. I haven't looked deeply into its architecture but I believe the 3GS should still be faster.

    Memory size is a huge limiting factor. The PSP has 2MB of video memory, 32MB of application memory and 4MB of embedded DRAM? The DS is even worse, it only has 4MB of RAM and < 1MB of video memory!

    The original iPhone had, what, 128MB? Everyone is expecting 256MB from the next-generation model.

    It's only a matter of time before handheld consoles are replaced by something like the iPhone. Console makers have to subsidize the cost of their hardware across games, cellular providers already subsidize the hardware costs of smartphones. There's huge potential here.

    Take care,
  • Anand Lal Shimpi - Thursday, June 11, 2009 - link

    Update - digging more into the PSP specs it's quite possible that the PSP is a faster gaming platform. It's difficult comparing CPUs since we're talking about a cross-architecture comparison, but on the GPU side the PSP appears to have more raw power. How that translates into real world performance compared to the PowerVR SGX in the 3GS remains to be seen. The 3GS most definitely has an efficient core.

    The memory comparison is still valid, especially with the 3GS at 256MB of RAM things get even more interesting.

    Take care,
  • Jovec - Wednesday, June 10, 2009 - link

    Wireless companies don't subsidize anything - they simply have an absolutely huge markup that then can then discount you $50 or $100 with a contract.
  • ViRGE - Wednesday, June 10, 2009 - link

    Depending on whether we're talking about the DS or the DSi, the main CPU is 66mhz or 133mhz respectively (always operating at 66mhz in DS mode). Both come with the ARM7 co-processor, which runs at 33mhz. The RAM value for the DS is right, meanwhile the DSi has 16MB. RAM's a bit iffy of course, the DS isn't running an operating system in the background and Slot-1 affords some in-place use of assets (albeit not true in-place execution like the GBA that let it get away with virtually no RAM). At any rate, the DS is still less powerful than the iPhone 3GS obviously.

    You're correct about the PSP, it has 2 MIPS processors (one for CPU use, one as a graphics processor) that can run between 22mhz and 333mhz. Most games for it are at 222mhz, a small number of titles push it to 333mhz. In raw CPU performance the 3GS is likely ahead, in GPU performance however it's entirely possible the PSP is still in the lead. When properly optimized the PSP is capable of near-PS2 graphics, which looking at the SGX's specs may be just a bit more than it can do. But we'll have to see what's done with it.

    The more limiting factor however is power consumption. The DS Lite is a champ here - on the lower screen brightness settings it gets over 10 hours running at full tilt. That's Nintendo's tradeoff on performance and power. The PSP isn't nearly as good, but even when everything is cranked up it can do about 4-5 hours (I'm going to ignore the UMD here), more if it's a 222mhz game.

    Both of these are well in excess of what the iPhone 3G got on its most demanding games. Even though the 3GS is faster, games aren't going to offer it much of an opportunity to drop to a lower power state since they're tasks that never end. For a 3G game I'd expect better battery life (50%, so 3 hours maybe?), but for a 3GS game it's likely going to be even worse.

    As you note the 3GS can eat more power, so if devs try to max it out (and they will, there's 20 years of console history that says shiny sells) it's reasonable to expect that it'll crash harder than even the 3G. Unless the SBX eats significantly less power, the worst case battery life scenario for the 3GS is going to be far worse than any dedicated handheld on the market, and worse than the existing 3G and iPod Touch.

    To that end, unless Apple can reign in on developers and make them NOT max out the hardware, I don't see handhelds going away any time soon. You'll get some convergence (e.g. solitaire) but the battery/hardware balance for a phone and a handheld are completely different. A gaming platform that only gets a couple of hours is a Sega Game Gear (or a Nomad, for the sadistic), and at least that had removable batteries.
  • psychobriggsy - Wednesday, June 10, 2009 - link

    Confirmation of 600MHz and 256MB RAM:">
  • sxr7171 - Wednesday, June 10, 2009 - link

    I GS must be faster than the N95's 3D acceleration as well, I know the 3G was slower, but this looks much faster. I've seen 3D demos on the N95 and wow they were impressive. At that 320x240 resolution it probably performed better than the PSP.
  • fyleow - Wednesday, June 10, 2009 - link

    The greatest weakness of the iPhone is the controls. Developers can get pretty innovative with the touch screen and accelerometer but really they can only do so much. id did a great job with Wolfenstein on the iPhone but the controls are still not as precise as physical buttons, and the controls take up the already limited screen estate of the phone.

    Nintendo threw as many input methods as possible with the mic, touch screen, physical buttons, and now camera. They also put in dual screens. The result is that developers could get wildly creative and I think it has been key to the DS' success because it allowed for some pretty innovative games.

    I've yet to see many "serious" games for the iPhone; most appear to be catered to very casual gaming. There's a huge market for that as evidenced by the Wii, but it's not ready to displace the dedicated hand held consoles yet.

    Yeah we'll probably see convergence happen down the road, but not in this or the next generation.

  • mesiah - Wednesday, June 10, 2009 - link

    The average phone user doesn't care much about games and game controls, so I don't really see apple or palm incorporating these into their phones and cluttering up the interface. But all it would take is for a company to create a peripheral that, say, the iphone snaps into and docks with that has an analog stick, some buttons, and some hand grips. Could even make it so it folds up when not in use. Something like that could really open up possibilities for gaming on iphone or pre. Just thinking about it makes me a little giddy hehe. Nintendo hand helds have always been too cheesy for me, but I can't bring myself to spend big money on a psp. Now if I can justify it with "but, its a phone and so much more." maybe my conscience would say "hey, your right! Go ahead and buy it."

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