What processor or processors do the iPhone models use?

Originally, Apple provided no information regarding the processor and other internal components of the original iPhone, the iPhone 3G, or the iPhone 3GS simply stating that the iPhone is a "closed platform."

For the iPhone 4, Apple originally mentioned that the device was powered by its own A4 processor of an unspecified clockspeed, and still does in some marketing materials, but the company later apparently scrubbed the processor information altogether from official technical specs.

For the iPhone 4S, Apple mentions that it is a "dual core" A5 processor of unspecified speed in the press release, but not elsewhere in technical information. Likewise, for the iPhone 5, the company press release heralds a "blazing fast A6 chip," but little more.

Third-Party Processor Sleuthing

However, for each iPhone model, third-parties have used hardware disassembly, software probing, and technical analysis to determine -- or at least speculate regarding -- the processor that each device uses.

When the original iPhone shipped on June 29, 2007 iFixit disassembled it and learned that the primary processor is an Apple branded Samsung ARM 11 processor running at 412 MHz. Although there was some later speculation that the primary processor might have been provided by Marvell instead of Samsung, Marvell provides the chip for 802.11b/g wireless networking, but not the primary processor.

For the iPhone 3G, iFixit and TechOnline collaborated to not only disassemble the device and confirm that like the original it also is powered by an Apple branded Samsung ARM 11 processor running at 412 MHz, but to go a step further and identify and label an exhaustive number of chips used in the iPhone.

Third-party teardowns from iFixit and RapidRepair -- as well as an analysis from AnandTech -- revealed that the iPhone 3GS has a significantly faster 600 MHz Samsung ARM Cortex A8 processor and a PowerVR SGX graphics processor.

For the iPhone 4 models, disassembly did not provide any precise details regarding the clockspeed of the Apple-branded "A4" processor and initial software probing with the Geekbench benchmark only spit out an unhelpful and obviously untrue "0.00 Hz."

However, based on in-depth analysis from both ArsTechnica and AnandTech, two highly reliable sources, and speed tests, it appears that the iPhone 4 is powered by an A4 processor (S5L8930) of variable clockspeed that typically runs around 750 MHz to 800 MHz. The always excellent Geekbench benchmarking tool also was updated to report a particular processor's variable clockspeed at the time of testing.

The Geekbench benchmark pinpoints that the iPhone 4S uses the "Apple A5" processor like the iPad 2 models, but more specifically it uses a 1 GHz dual-core Apple A5 (S5L8940) processor of variable clockspeed, commonly "downclocked" to 800 MHz to conserve battery life.

Finally, for the iPhone 5 models -- the iPhone 5 (GSM/LTE 4, 17/North America), iPhone 5 (CDMA/LTE, Sprint/Verizon/KDDI), and iPhone 5 (GSM/LTE 1, 3, 5/International) -- AnandTech determined that it has a custom dual core processor and a three core graphics processor, most likely a 266 MHz PowerVR SGX 543MP3. Early Geekbench software analysis indicated that it had a 1 GHz processor, but a subsequent version of the software more accurately determined that it has a variable speed processor that commonly runs around 1 GHz with a top speed of 1.3 GHz.

Ultimately, most users probably don't need to know or even care to know about processor details for the iPhone models, but for those who do, it is hoped that this variety of methods to evaluate clockspeeds and internal components is interesting nevertheless.