The iPhone 4S is built with many of the same components found in prior iPhone designs, but the similarities have caused many companies to incorrectly report cost and component market share. A slight change to the Qualcomm-supplied modem has resulted in a new front-end configuration.

All of the power amplifiers (PAs) are multi-mode, thus counting components does not reveal much. The Avago PA, for instance, covers six bands (four GSM/EDGE bands and two WCDMA bands) and the TriQuint PA covers both CDMA and WCDMA for US PCS band.

The application processor is one item that most get right - Apple A5. But it is not the 1GHz part found in the popular tablet. The iPhone 4S version runs at 800MHz, just like the A4 found in the iPhone 4.

Apple is running the same processor in the tablets and handsets, but downshifting the handsets by 20%. The slower processor does not mean lower performance, however. The smaller screen combined with faster memory gives the iPhone 4S a slight advantage in a number of performance tests, all while drawing less than two-thirds the power needed for the iPad 2.

Key iPhone 4S facts include:

- Slight modification to the popular Qualcomm MDM6600 modem platform (MDM6610)

- New RF front-end configuration utilizing all multi-mode PAs

- An A5 application processor running 20% slower than the A5 in the iPad 2, but similar overall performance with much less power

- A Murata Bluetooth module supporting BT 4.0.

- Other components, such as housing and display, are very similar to the iPhone 4