iPhone/iPhone 3G:
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- CPU: ARM 1176JZ at 412 MHz
- GPU: PowerVR MBX at 103 MHz
- 128 MB DRAM
- Rear 2.0 Megapixel Camera
iPhone 3GS:
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- CPU: ARM Cortex - A8 at 600 MHz
- GPU: PowerVR SGX535 at 150 MHz
- 256 MB DRAM
- Rear 3.0 Megapixel Camera
iPhone 4:
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- CPU: ARM A4 at 800 MHz
(Cortex A8 renamed A4, reused prior architecture for CPU and GPU)
- GPU: PowerVR SGX535 at 200 MHz
- 512 MB DRAM
- Rear 5.0 Megapixel Camera / Front 0.3 Megapixel Camera
iPhone 4S:
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- CPU: ARM A5 (dual Core) at 800 MHz (Cortex A9, new micro architecture)
(This is monumental, now only is it a new microarchitecture, but it introduced multi threading... magnitudes in a jump.)
- GPU: PowerVR SGX543MP2
- 512 MB DRAM
- Rear 8.0 Megapixel Camera / Front 0.3 Megapixel Camera
iPhone 5:
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- CPU: ARM A6 (dual Core) at 1300 MHz
(new architecture, Swift core somewhat akin to CortexA15)
- GPU: PowerVR SGX543MP3
- 1 GB DRAM
- Rear 8.0 Megapixel Camera / Front 1.2 Megapixel Camera
From the previous iterations, I would conclude that the 'S' series isn't a minor bump in internal specs, but a complete new iPhone in a tested exterior.
Now that the telephone contacts containing subsidized iPhones are over a two years period, half of the customers will go from 3G to 4 to 5 and the other half will go from 3GS to 4S to 5S.
So a lot of us skip a generation, meaning that our latest iPhone is not a minor improvement compaired to our old one AND Apple gives both groups the chance to own the same exterior design without forcing us to break the contract cycle...isn't that a nice gesture of Apple Inc