Where does the iPhone 3G S get its speed?

Rumors are rampant that Apple is using a new chip to crank up the performance of the new smartphone.

Brooke Crothers Former CNET contributor
Brooke Crothers writes about mobile computer systems, including laptops, tablets, smartphones: how they define the computing experience and the hardware that makes them tick. He has served as an editor at large at CNET News and a contributing reporter to The New York Times' Bits and Technology sections. His interest in things small began when living in Tokyo in a very small apartment for a very long time.
Brooke Crothers
3 min read

So, where does the Apple iPhone 3G S get its claimed "2x faster" leap in speed? Rumors are rampant that Apple is using a new chip to crank up the performance.

Why rumors when Apple has already announced the iPhone 3G S? Apple doesn't disclose chip-level hardware specifications. Moreover, Apple clearly wants to convince any prospective buyer than it's not the iPhone's individual parts that matter but the Apple-branded whole.

Apple claims a speed jump up to two times faster than the previous iPhone: a lot of that may be due to the new processor.
Apple claims a speed jump up to two times faster than the previous iPhone: a lot of that may be due to the new processor. Apple

The fact is no one will know for sure until teardown specialists like iFixit and iSuppli actually disassemble the iPhone 3G S. "Until we actually decap those chips, we won't know exactly which chip it is," according to Francis Sideco, senior analyst for wireless communications at iSuppli.

Kyle Wiens, one of the founders of iFixit, said Wednesday he is flying to Europe to get his hands on the iPhone 3G S and take it apart.

So, what does Apple claim exactly? Here's the Apple ad copy on its Web site. "The Fastest iPhone Ever. The first thing you'll notice about iPhone 3G S is how quickly you can launch applications. Web pages render in a fraction of the time, and you can view e-mail attachments faster. Improved performance and updated 3D graphics deliver an incredible gaming experience, too. In fact, everything you do on iPhone 3G S is up to two times faster and more responsive than iPhone 3G."

Technology Web site Anandtech claimed Wednesday that it knows what the chip is. "Although unannounced, the iPhone 3GS uses (again) a Samsung (system-on-a-chip) but this time...it's got a Cortex A8 and PowerVR SGX; just like the (Palm) Pre," according to an analysis published Wednesday at Anandtech by Anand Shimpi, editor in chief .

Most smartphones today--including the previous versions of the iPhone--are based on some version of an application processor design from U.K.-based ARM. The Cortex A8 is a newer, faster version of the ARM design.

A T-Mobile Netherlands' Web page has published features that specify "256 RAM" and "600 MHz-processor." The link is cited in a report published Wednesday by AppleInsider.

"My gut tells me the Cortex A8 is very possible," said IFixit's Wiens, responding to an e-mail query. Though he emphasized that he is simply guessing. iSuppli's Sideco said that the 600MHz speed cited on the T-Mobile Web site doesn't necessarily mean that Apple is using the latest and greatest ARM design. "I wouldn't necessarily make that connection," he said, adding that there are 600MHz ARM processors available based on older designs.

That said, if the Anandtech report is true, this means the iPhone 3G S's application processor--essentially the brain of a smartphone--is similar to the processor used in the Palm Pre. The Texas Instruments' chip in the Pre is also a Cortex-A8 design core from ARM.

Here's what ARM says. The Cortex-A8 processor "is the highest performance, most power-efficient processor available from ARM. With the ability to scale in speed from 600MHz to greater than 1GHz." And using argot probably lost on many readers, it is an in-order, dual-issue, superscalar microprocessor core. Over-simplified translation: it can do more than one thing at a time.

These specifications compare favorably to the processor used in the previous iPhone: an older-generation ARM chip running at 412MHz.

The Palm Pre chip also integrates a Powervr SGX 2D/3D graphics accelerator based on a design from Imagination Technologies. The Anandtech report claims that the iPhone 3G S also uses this graphics silicon.

One of the big mysteries is how much tweaking Apple does to the basic ARM chip design. In one respect, this question is answered very visibly since Apple stamps its brand on the iPhone processor. And for future iPhones, Apple is expected to tap proprietary technology from the recently acquired P.A. Semi. "With their acquisition of PA Semi, the apps (application) processor is the most likely slot to get internalized," according to Sideco, referring to the likelihood that Apple will focus in-house development on the main processor inside the iPhone.

Marion Morales, vice president of IDC's semiconductors research program, said last month in a phone interview that though Apple uses Samsung chips, "when you look at the processor itself, they're designing the processor and using Samsung as a foundry (factory)," he said, underscoring the fact that Apple emphasizes internally developed technology and de-emphasizes external suppliers, even large companies like Intel and Samsung.