In the heated battle of the smartphones, Apple is still subject to dependence on chip supply from its most dominant competitor Samsung. Chipworks posted in its blog that the A7 chip of the new iPhone 5S is actually made by Samsung.

Apple getting chips from Samsung should not be that surprising because the chip’s predecessor A6 was also supplied by the South Korean company. This was confirmed by the teardown expert by reverse engineering the chip and unearthed the truth of its make.

Pre-launch of the iPhone 5S, a lot of rumors have been going around that Apple is going to switch to a new supplier, TSMC (Taiwan Semiconductor Manufacturing Co), for the manufacturing of its SoC. Although this may soon be realized, its huge competitor is still making the specific chip used for the latest iPhone 5S.

According to Chipworks, "We have confirmed through early analysis that the device is fabricated at Samsung’s Foundry and we will confirm process type and node later today as analysis continues. That being said, we suspect we will see Samsungs 28 nm Hi K metal Gate (HKMG) being used. We have observed this same process in the Samsung Exynos Application processor used in the Galaxy S4. Our engineers will be deprocessing the Apple A7 as soon as they can to confirm this or to provide different information."

Another interesting discovery by Chipworks is that the M7 of Apple, known as the "motion co-processor" looks like similarly made by a third-party, rather than a part solely owned by Apple.

"Luckily, we’ve been able to locate the M7 in the form the NXP LPC18A1. The LPC1800 series are high-performing Cortx-M3 based microcontrollers. This represents a big win for NXP. We had anticipated the M7 to be an NXP device based on input from industry analysts and our partners and we are happy to see this to be the case," Chipworks said.

New supplier TSMC is expected to begin supplying Apple chips by 2014. However, John Gruber, a well-known Apple blogger, said there were rumors that the main reason for the shift of supplier was because the iPhone maker is cutting off chip orders to Samsung plant in Austin.